# Digital SAT - Math Textbook

```Math TEXTbook
DIGITAL SAT PREP
1.1
PART I: ALGEBRA
BASIC CONCEPTS
ORDER OF OPERATIONS
PGERMDAS
1.
2.
3.
4.
•
•
•
•
What is the value of
+(-&quot;!)(-/%)&quot;%+
-
COMMUTATIVE LAW: When adding or multiplying, order doesn’t
matter. Example: 3 + 8 + 12 = 8 + 12 + 3.
ASSOCIATIVE LAW: When adding or multiplying, grouping doesn’t
matter. Example: 2 + (3 + 4) + 5 = (2 + 3) + (4 + 5)
DISTRIBUTIVE LAW: When a grouped sum/difference is being
multiplied/divided, you may “distribute” the multiplication/division.
Example: 15 (20 + 8) = 15 (20) + 15 (8)
SIMPLIFICATION OF EXPRESSIONS
•
√'#&quot;(
PG: Parenthesis and other grouping symbols (inside out)
ER: Exponents and roots (inside out)
MD: Multiplication and division (left to right)
AS: Addition and subtraction (left to right)
LAWS OF ARITHMETICS
•
!&quot;#&times;%
What is the value of !&quot;%&times;! + #)&divide;%! ?
LAW OF SUBSTITUTION: If two things are equal, you can always
substitute one for the other.
OPERATIONS: Every operation can be expressed in terms of its
inverse. Example: Subtracting -16 is the same as adding 16.
FACTORING IDENTITIES:
o (π + π)% = (π + π)(π + π) = π% + 2ππ + π%
o (π − π)% = (π − π)(π − π) = π% − 2ππ + π%
o (π + π)(π − π) = π% − π%
ABSOLUTE VALUE
?
If x and y are positive numbers such that 3x – 2y = 7, what is
%0&quot;1
the value of #- ?
2! /3!
(
If m and n are real numbers such that %2/%3 = %, what is the
value of m + n?
What is the distance between d and -10 on the number line?
The absolute value of a number a (|a|) is the distance from a to 0 on
the number line.
The absolute value of the difference between two numbers (|a-b|) is
the distance between a and b on the number line, regardless of which
number is greater.
This document has been created for educational purposes only and meant to be used exclusively by
SCORE – Test Prep and College Counseling. This document may not be distributed or reproduced
without the express written consent of its authors.
0.000001
0.00001
Millionths
Hundred-Thousandths
0.001
0.0001
Ten-Thousandths
Thousandths
0.1
0.01
Hundredths
.
Tenths
1
Decimal Point
10
Ones
100
DECIMAL PART
Tens
1,000
Hundreds
10,000
Thousands
100,000
Ten Thousands
1,000,000
Millions
WHOLE PART
Hundred Thousands
ROUNDING
The process of rounding implies adjusting the digits to make rough
calculations easier.
• If the unit of the number is less than five, the number needs
to be rounded down.
• If the unit of the number is 5 or above, the number needs to
be rounded up.
1
1.2
PART I: ALGEBRA
Linear Equations
WORD PROBLEMS
The easiest way to solve word problems is by breaking them down
following these steps:
1. Identify the relevant quantities.
2. Represent those quantities with algebraic expressions.
3. Translate the facts into equations.
4. Solve the equations for the relevant quantities.
The Horizon Resort charges \$150 per night for a single room,
and a one-time valet parking fee of \$35. There is a 6.5% state
tax on the room charges, but no tax on the valet parking fee.
What equation would represent the total charges in dollars, C,
for a single room, valet parking, and taxes, for a stay of n nights
at the Horizon Resort?
CONSTRUCTION AND INTERPRETATION
The graph of the line π in the xy-plane passes through the point
(2, 5) and has an x-intercept of 7. Which of the following gives
the equation of a line that is perpendicular to line π and passes
through the point (4, 2)?
a. π¦ = −π₯ + 6
b. π¦ = −π₯ + 4
c. π¦ = π₯ − 2
d. π¦ = π₯ + 2
•
Linear equations can be written in any of the following forms:
Linear form
Slope-intercept
Standard
Point-slope
Intercept
Equation
y = mx + b
ax + by = c
y - y1 = m(x - x 1)
x / a+y / b =1
Slope
m
-a/b
m
-
Y-intercept
b
c/b
b
X-intercept
a
*The intercept form cannot be used for horizontal lines or lines passing through the origin.
a.
b.
c.
The slope of a linear equation shows how much a line goes up or
down when you take one step to the right along the line. It can be
calculated using the following formula:
πππ π π¦# − π¦!
π ππππ =
=
ππ’π π₯# − π₯!
Parallel slopes have equal values: π! = π#
!
Perpendicular slopes are opposite and reciprocal: π! = −
d.
e.
f.
g.
h.
i.
A line with a positive slope goes up as you move to the right.
A line with a negative slope goes down as you move to the right.
A horizontal line has a 0 slope.
A vertical line has an undetermined slope.
Distance between two points on a line: 1(π₯! − π₯# )# + (π¦! − π¦# )#
&quot; &amp;&quot; ' &amp;'
Midpoint: ( &quot; # ! ; &quot; # !)
%!
ALGEBRAIC MANIPULATION
For πΉ =
()%
*!
, find G in terms of F, M, m and r2.
“What is m in terms of p and q” is another way of saying “solve for m”
or “use algebra to get m alone”.
LAWS OF EQUALITY
1.
2.
3.
4.
Whatever you do to change the value of one side of an equation,
you must also do to the other side.
You may add, subtract, or multiply anything you want on both sides
of any equation at any time.
You may divide both sides of any equation by any number except 0.
If you want to take the square root of both sides of an equation,
remember that every positive number has two square roots: one
positive and one negative.
!
#
&quot;
\$&quot;
If +
= 4, what is the value of x?
This document has been created for educational purposes only and meant to be used exclusively by
SCORE – Test Prep and College Counseling. This document may not be distributed or reproduced
without the express written consent of its authors.
2
PART I: ALGEBRA
1.3
Inequalities
LAWS OF INEQUALITY
1.
2.
3.
4.
Whatever you do to change the value of one side of an inequality,
you must also do to the other side.
You may add or subtract anything you want from both sides of an
inequality, or multiply or divide by any positive number without
changing the direction of the inequality.
You may not perform undefined operations to an inequality
(dividing by 0) or operations that have more than one possible
result (taking a square root).
If you multiply or divide both sides by a negative number, you must
switch the direction of the inequality.
GRAPHING INEQUALITIES
•
For inequalities in the form π₯ ≥ π, the expression can be drawn on
the number line. Example: π₯ ≥ −3.
-5
•
-4
-3
-2
-1
0
1
2
3
4
!
!
If − &quot; &lt; −2π₯ + 1 &lt; − # , what is one possible value of x?
Graph the following inequalities:
a. π¦ &gt; −3
b. π¦ ≥ −π₯ + 1
c. π¦ ≤ 2π₯ + 3
d. π¦ &lt; 12
5
For inequalities on the xy-plane, follow these steps:
1. Change the symbol to “=” and draw the inequality as an
equation.
2. Choose a point that does not lie on the line of the
inequality.
3. Substitute the coordinates of the chosen point in the
inequality.
4. Check if the values comply with the inequality.
5. If the values comply, the inequality contains all points to
that side of the line.
6. If the values do not comply, the inequality contains all
points to the other side of the line.
This document has been created for educational purposes only and meant to be used exclusively by
SCORE – Test Prep and College Counseling. This document may not be distributed or reproduced
without the express written consent of its authors.
3
1.4
PART I: ALGEBRA
Linear Systems
TYPES OF SOLUTIONS
A system of equations is a set of two or more equations that must be
true simultaneously.
Systems can have different types of solutions:
a. No solution: The equations do not intersect. In the case of
linear systems, the lines are parallel. Equal slopes, different
y-intercepts.
b. Infinite solutions: The equations lie on the same line, so they
are coincidental. Equal slopes, same y-intercept.
c. One solution: The lines intersect at one point. Different
slopes, y-intercept may be the same or different.
d. Multiple solutions: The lines intersect at multiple points. This
does not apply to linear systems.
METHODS FOR SOLVING SYSTEMS OF EQUATIONS
Solving a system of equations means finding all the values that make
all of the equations true at the same time. There are several methods
that can be used to solve these systems:
a. Substitution: If one variable is isolated or can be easily isolated
in one of the equations, the law of substitution can be used to
solve the system.
b. Combination: In a system of equations it is possible to add or
subtract the corresponding sides of the equation together to
get a new equation while trying to eliminate variables.
c. Graphing: If a system of equations can be graphed, the
solution to the system is the intersection of the graphs.
Systems of inequalities are usually solved graphically, as it is easier to
visualize the intersection of two or more inequalities on a graph. To
graph a system of inequalities, plot each inequality individually and find
the common area shaded by all inequalities.
ππ₯ + ππ¦ = 12
2π₯ + 8π¦ = 60
In the system of equations above, a and b are constants. If the
system has infinitely many solutions, what is the value of a/b?
ππ₯ − 3π¦ = 4
4π₯ − 5π¦ = 7
In the system of equations above, k is a constant and x and y
are variables. For what value of k will the system of equations
have no solution?
Solve the following system using substitution:
3π₯ + π¦ = 3π¦ + 4
π₯ + 4π¦ = 6
Solve the following system using combination:
3π₯ + π¦ = 3π¦ + 4
π₯ + 4π¦ = 6
Solve the following system using graphing:
3π₯ + π¦ = 3π¦ + 4
π₯ + 4π¦ = 6
This document has been created for educational purposes only and meant to be used exclusively by
SCORE – Test Prep and College Counseling. This document may not be distributed or reproduced
without the express written consent of its authors.
4
2.1
PART II: Problem Solving and Data Analysis
Data Analysis
AVERAGE OR ARITHMETIC MEAN
The average or arithmetic mean of a set of numbers can be calculated
with the following formula:
ππ’π ππ ππ’πππππ
π΄π£πππππ =
# ππ ππ’πππππ
The weighted average is the average of two or more groups that do not
have the same number of elements.
MEDIAN
The median of a set of numbers is the value of the number located in
the middle when the numbers are ordered increasingly or decreasingly.
The average of four numbers is 15. If one of the numbers is 18,
what is the average of the remaining three numbers?
Ms. Aguilar’s class, which has 20 students, scored an average
of 90 points on a test. Mr. Bowle’s class, which has 30 students,
scored an average of 80 points on the same test. What was the
combined average score, in points, for the two classes?
The median of 1, 6, 8 and k is 5. What is the average of these
four numbers?
When the number or values is odd, the median can be calculated using
the following formula:
# ππ ππ’πππππ  + 1
ππππππ π‘πππ =
2
When the number of values is even, the median will be the average of
the two middle values. Divide the number of values by two to find the
first middle term. The second middle term will be the next consecutive
term.
MODE
The mode of a set of numbers is the number that appears the most
frequently. If all numbers occur equally, then the set does not have a
mode.
If a set of numbers contains 1, 2, 3, 4, 5, 4, 3, 4, 5, 6, 7, 5, 4.
What is the mode of the set?
A set of numbers can have more than one mode and be multimodal. For
two modes, the set is called bimodal; for three modes, the set is called
trimodal.
Data spread refers to how a set of data is distributed, focusing on how
far the values are from the mean or median. Outliers are values that are
much larger or smaller than the rest of the values in the set. They
generally affect the mean more than the median.
The range of a set of data is defined as the absolute difference
between the least value and the greatest value in the set. If five
positive integers have an average of 10, what is the greatest
possible range of this set?
• Range: The difference between the highest and lowest values in a
data set.
• Standard deviation: The average distance of each element from the
mean. The more spread out the data is on a graph, the larger the
standard deviation.
This document has been created for educational purposes only and meant to be used exclusively by
SCORE – Test Prep and College Counseling. This document may not be distributed or reproduced
without the express written consent of its authors.
5
2.1
PART II: Problem Solving and Data Analysis
Data Analysis
CORRELATION
POSITIVE AND NEGATIVE CORRELATION
• Positive correlation: If one variable increases, the other variable has a tendency to also increase (direct variation).
• Negative correlation: If one variable increases, the other variable has a tendency to decrease (inverse variation).
• No correlation: If one variable increases, the other variable does not tend to either increase or decrease.
STRONG AND WEAK CORRELATION
• Strong correlation: If one variable increases or decreases, there is a higher chance of the second variable increasing or decreasing.
In a graph, the points tend to form a line at an angle.
• Weak correlation: If one variable increases or decreases, there is a lower chance of a relationship between the variables. In a
graph, the points tend to spread or form a very flat or vertical line.
DATA INFERENCE AND SURVEY INTERPRETATION
•
•
•
•
Population parameter: A numerical value that describes a characteristic of a population (for example, the percentage of
registered voters who would vote for a certain candidate). We often do not know the value of this parameter, and
statistics are used to estimate it based on a sample from the population.
Selection of a sample: In order for a sample to be representative, subjects must be selected at random, and a significant
part of the total population must be considered.
Margins of error: The value of the margin of error is affected by the variability of the data (the larger the standard deviation,
the larger the margin of error; the smaller the standard deviation, the smaller the margin of error) and the sample size
(increasing the size of the random sample provides more information and typically reduces the margin of error). Also, the
margin of error applies to the estimated value of the population parameter only, but it does not inform the estimated value
for an individual.
Generalization:
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6
2.2
PART II: Problem Solving and Data Analysis
Rates and ratios
RATES
Rate expresses a measure, quantity or frequency between two elements.
The formula for rate is given by the units in a problem. For example, if
the unit used is kilograms per second:
πππ‘π =
ππ’ππππ ππ πππππππππ
ππ’ππππ ππ π ππππππ
A water pump for a dredging project can remove 180 gallons
of water per minute, but it can only work for 2.5 consecutive
hours, at which time it requires 20 minutes of maintenance
before it can be brought back online. While it is offline, a
smaller pump is used in its place, which can pump 80 gallons
per minute. Using this system, what is the least amount of time
it would take to pump 35,800 gallons of water?
Rates provide conversion factors that can be used to solve the problem.
For example, if the exercise states that a rocket burns fuel at a rate of 15
kilograms per second, two conversion factors can be identified:
!&quot; \$%&amp;'()*+,
! ,-.'/0
! ,-.'/0
or !&quot; \$%&amp;'()*+,
RATIOS
A ratio is a mathematical relationship between two quantities
expressed as the quotient of those quantities.
Ratios can be:
• Part-to-whole: They compare a part to the whole. For
example, the number of female students in a class compared
to the total number of students in the class. These can also be
expressed as percentages of the whole.
• Part-to-part: They compare one part to another part. For
example, the number of female students in a class compared
to the number of male students in the class.
Probabilities can also be expressed as ratios, where a subset of equally
likely events is compared to a larger set of equally likely events.
UNIT CONVERSIONS
A conversion factor is a fraction in which the numerator and the
denominator are equal. For example, 1 mile equals 1.609 kilometers:
πΆπππ£πππ πππ ππππ‘ππ (ππ π‘π ππ):
1 ππππ
1.609 πππππππ‘πππ
πΆπππ£πππ πππ ππππ‘ππ (ππ π‘π ππ):
1.609 πππππππ‘πππ
1 ππππ
When using conversion factors, units must cancel properly to yield the
unit needed in each case.
Bronze is an alloy consisting of copper and tin. If 50 kg of a
bronze alloy of 20% tin and 80% copper is mixed with 70kg of
a bronze alloy of 5% tin and 95% copper, what fraction, by
weight, of the combined alloy is tin?
At the Andromeda Book Store, the ratio of self-help titles to
fiction titles is 3:10, and the ratio of biography titles to fiction
titles is 2:7. What is the ratio of biography titles to self-help
titles?
Niko is 27 inches shorter than his father, who is 5 feet 10 inches
tall. How tall is Niko? Express your answer in feet (1 foot = 12
inches).
If a factory can manufacture b computer screens in n days at a
cost c dollars per screen, then which of the following
represents the total cost, in dollars, of the computer screens
that can be manufactured, at that rate, in m days?
1.+
a.
b.
c.
d.
/
1+/
.
+.
1/
1.
+/
This document has been created for educational purposes only and meant to be used exclusively by
SCORE – Test Prep and College Counseling. This document may not be distributed or reproduced
without the express written consent of its authors.
7
2.3
PART II: Problem Solving and Data Analysis
Percentages and Proportions
PERCENTAGES
•
•
•
•
TRANSLATING PERCENT PROBLEMS: Translation key for word
problems:
o “is” means equal ( = )
o “of” means multiplication ( * )
o “what” means an unknown ( x )
o “per” means division ( / )
o “percent” means division by 100 ( /100)
COMMUTATIVE LAW OF PERCENTAGES: x% of y = y% of x. For
example, it is easier to calculate 25% of 80 than 80% of 25.
CHANGING BY PERCENTAGES:
o To increase a number by a%, multiply by (100 + a)% or by
(1 + a%).
o To decrease a number by a%, multiply by (100 – a)% or by
(1 – a%).
PERCENT CHANGE: To find a percent change, use the following
formula:
πππππ ππππππ − ππππππππ ππππππ
%ππππππ =
∗ πππ
ππππππππ ππππππ
What percent of 150 is 93?
On the day it was issued, one share of a stock in Consolidated
Energy was priced at \$50. If the share price increased by 120%
in its first five years and by 150% in its next five years, what was
the share price, in dollars, after 10 years?
If a population of bacteria increases from 80 cells to 220 cells,
what is the percent increase in this population?
How many liters of a 40% saline solution must be added to 4
liters of a 10% saline solution to make a 20% saline solution?
PROPORTIONS AND SCALING
•
π
PROPORTIONS:
o A proportion is a statement that two ratios are equal.
π π
=
π π
o Law of cross-multiplication: In any proportion, the crossproducts must be equal.
π
π
If π = π , then ππ = ππ
o Law of cross-swapping: Cross-swapping can be done in any
proportion.
π
π
π
π
π
If a, b and c are real numbers such that π%π =
following must also be true?
a. π' + π' − π ' = 0
b. π' − π' − π ' = 0
c. π' − π' + π ' = 0
d. π' + π' + π ' = 0
π&amp;π
π
, which of the
π
If π = π , then π = π and π = π
•
•
SCALING: Scaling represents the relationship between a
measurement on a model and the corresponding measurement
on the actual object.
RULE OF THREE: The Rule of Three is a Mathematical Rule that
allows you solve problems using proportions. Knowing three
values and the relationship between them allows to calculate the
value of a fourth unknown value. For direct proportions, direct
Rule of Three is used. For inversed proportions, Inverse Rule of
Three is used.
DIRECT RULE OF THREE
On a scale blueprint, the drawing of a rectangular patio has
dimensions 5 cm by 7.5 cm. If the longer side of the actual patio
measures 21 feet, what is the area, in square feet, of the actual
patio?
INVERSE RULE OF THREE
This document has been created for educational purposes only and meant to be used exclusively by
SCORE – Test Prep and College Counseling. This document may not be distributed or reproduced
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8
2.4
PART II: Problem Solving and Data Analysis
Probabilities
CONDITIONAL PROBABILITIES
A conditional probability is the probability that something is true given
that something else is also true.
Solving conditional probability problems often require finding
population fractions, where the numerator of the fraction is the
required population and the denominator of the fraction is the total
universe being considered.
Test 1
Test 2
Test 3
Test 4
Total
A
10
12
7
10
39
B
11
8
12
9
40
C
2
3
6
3
14
C
1
0
0
0
1
Inc.
1
2
0
3
6
Total
25
25
25
25
100
The letter grades on four tests for Ms. Hartman’s 25 students
(including incomplete grades marked “Inc.”) are tabulated
above. Five students in the class received an A on both test 3
and test 4. If one of the students who received an A on either
test 3 or 4 is chosen at random, what is the probability that
he or she received an A on test 4?
If the incomplete grades are excluded from the statistics for
each test in the table above, for which of the tests was the
a. None of the tests
b. Test 2 only
c. Tests 1 and 2 only
d. It cannot be determined from the given information.
ARRANGEMENTS
•
•
ARRANGEMENTS: Arrangements are used to determine how many
arrangements of something are possible. For items of different
categories, the number of options in each category are multiplied.
FACTORIALS: The factorial of n is the number of ways in which the
n elements of a group can be ordered. It is expressed as n!, where
n! = 1 * 2 * … * (n – 2) * (n – 1) * n.
A cafeteria has a lunch special consisting of soup or salad; a
sandwich; coffee, tea, or a non-alcoholic beverage; and a
dessert. If the menu lists 2 soups, 3 salads, 6 sandwiches, and
10 desserts, how many different lunches can one choose?
In how many ways can 4 letters be combined?
This document has been created for educational purposes only and meant to be used exclusively by
SCORE – Test Prep and College Counseling. This document may not be distributed or reproduced
without the express written consent of its authors.
9
2.5
PART II: Problem Solving and Data Analysis
Tables and graphs
TABLES
Tables are useful when analyzing information that falls into nonoverlapping categories.
! ! &quot;!
Plot the graph for π(π₯) = #!&quot;!.
Tables can be useful for analyzing functions because they help to
plot graphs and identify important patterns. For any equation
expressing y in terms of x, a table of ordered pairs can be created.
VENN DIAGRAMS
Venn diagrams are useful when analyzing information that falls into
overlapping categories.
In a poll of 250 college students, 137 said that they attended at
least one athletic event in the past year, and 115 said that they
attended at least one career services event in the past year. If
82 of these students attended both an athletic event and a
career services event in the past year, how many students
attended neither an athletic event nor a career services event
in the past year?
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10
2.5
PART II: Problem Solving and Data Analysis
Tables and graphs
SCATTERPLOTS
Scatterplots are graphs of ordered pairs of data. They can show
relationships between variables that don’t vary in a highly predictable
way.
A line of best fit is a line that englobes these points optimally, showing
the basic relationship between the variables. To draw a line of best fit,
you must roughly estimate that there are the same number of points
above and below the line.
The scatterplot to the left shows 40 readings for particulate
matter (a pollutant) concentration, in micrograms per cubic
meter, in a metropolitan area over 9 years. Based on the line
of best fit shown as a solid line, which is closest to the average
yearly decrease in particulate matter concentration?
a. 0.32 mcg/m3 per year
b. 0.64 mcg/m3 per year
c. 3.2 mcg/m3 per year
d. 6.4 mcg/m3 per year
According to the line of best fit to the data to the left, which
of the following is closest to the percent decrease in average
particulate matter concentration for 2007 to 2012?
a. 9%
b. 18%
c. 36%
d. 60%
PIE GRAPHS
A pie chart is a circular statistical graph that is divided into slices to
illustrate numerical proportion.
When analyzing graphs, the following formula is essential:
ππππ‘
πππππππ  ππ π‘βπ π πππ‘ππ
=
π€βπππ
360
Maria is constructing a pie graph to represent the expenses
for her project. Here, expenses fall into three categories:
marketing, design, and development. She knows that the
marketing expenses are \$12,000 and the design expenses are
\$30,000, but the development expenses could range
anywhere from \$30,000 to \$48,000. Based on this
information, which of the following could be the measure of
the central angle of the sector representing marketing
expenses.
a. 45&deg;
b. 54&deg;
c. 62&deg;
d. 65&deg;
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11
2.5
PART II: Problem Solving and Data Analysis
Tables and graphs
OTHER GRAPHS
Bar graphs: They compare numeric values of any type and can be either horizontal or vertical. One axis represents the categories
being compared and the other axis represents the value of each category.
Histograms: They are a specific type of bar graph that illustrated the distribution of numeric data across categories.
Line graphs: They show how related data changes over a period of time.
Maps: They usually show a geographical area.
BOXPLOTS
A boxplot is a standardized way of displaying the distribution of data
based on a five-number summary:
• Minimum
• First quartile (Q1): The middle number between
the smallest number and the median.
• Median: The middle value of the data set. Note that
the median does not need to be in the middle of
the box.
• Third quartile (Q3): The middle number between
the largest number and the median.
• Maximum
A sample of 10 boxes of raisins has these weights in grams:
25, 28, 29, 29, 30, 34, 35, 35, 37, 38
Make a box plot of the data.
To draw a boxplot, follow these steps:
• Order the data from smallest to largest.
• Find the median.
• Find the quartiles.
• Complete the five-number summary by finding the min and
max.
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12
3.1
Functions
BASIC CONCEPTS
•
Find the extraneous solution: √−π₯ = π₯ + 2
Function: A function is a recipe for turning any input number
(usually x) into an output number (usually y or f(x)).
Extraneous or spurious solutions: Solutions that emerge from
the process of solving a problem but are not valid solutions to
the problem.
Undefined functions: Functions are said to be undefined at
points outside of their domain. Pay special attention to
expressions with polynomials in the denominator.
•
•
For what value is
REPRESENTATION OF FUNCTIONS
Functions can be represented as:
• Ordered pairs in a table:
•
•
x
0
1
2
3
4
&amp;!
undefined?
x
1
2
3
4
5
6
7
8
9
y
3
5
7
9
11
Equations in functional notation: π(π₯) = 2π₯ + 3
Graphs in the xy-plane:
QII
! ! \$%
g(x)
2
4
6
8
10
12
14
16
18
h(x)
-9
-6
-3
0
3
6
9
12
15
What would the equation of g(x) be?
QI
π¦ = 2π₯ + 3
What would the equation of h(x) be?
QIII
QIV
COMPOSITION OF FUNCTIONS
The notation π(π(π₯)) indicated the composition of two functions (g and
f). Composition means that an initial value x is put into the function g,
and the resulting value is put into the function f.
If π(π₯) = π₯ + 2 and π(π(1)) = 6 , which of the following could be g(x)?
a. π(π₯) = 3π₯
b. π(π₯) = π₯ + 3
c. π(π₯) = π₯ − 3
d. π(π₯) = 2π₯ + 1
If π(π₯ − 1) = 2π₯ + 3 for all values of x, what is the value of
π(−3)?
If π(2π₯) = π₯ + 2 for all values of x, which of the following is
equivalent to f(x)?
!&quot;#
a.
#
b.
c.
d.
!
+2
#
!\$#
#
2π₯ − 2
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13
3.1
Functions
TRANSFORMATION OF FUNCTIONS
For π(π₯) = π₯ # + 2π₯ + 1
•
•
•
•
Movement in the x-axis:
o To the right: π(π₯ − 1)
o To the left: π(π₯ + 1)
Movement in the y-axis:
o Upwards: π(π₯) + 1
o Downwards: π(π₯) − 1
Reflection over an axis:
o Over the x-axis: -π(π₯)
o Over the y-axis: π(−π₯)
Stretching and shrinking:
o Vertical stretch: ππ(π₯), when k &gt; 1
o Vertical shrink: ππ(π₯), when k &lt; 1
For π(π₯) = π₯ # − 1, what functions will yield…
a. π(π₯) displaced one unit upwards and then reflected
over the y-axis
b.
π(π₯) reflected over the x-axis and then displaced
five units to the right
c.
π(π₯) stretched by a factor of 3 and then displaced 2
units to the left
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14
3.2
A quadratic expression (or second-degree polynomial) is any
expression of the form If ππ₯ ! + ππ₯ + π.
Quadratic equations can be expressed in three forms:
a. Standard form: π¦ = ππ₯ ! + ππ₯ + π, where:
• a determines the orientation and width of the parabola:
o If a positive, the parabola opens upwards.
o If a is negative, the parabola opens downwards.
o An increasing a narrows the parabola.
o A decreasing a widens the parabola.
• b indicates the slope of the parabola at the y-intercept.
• c indicates the y-intercept (0;c) and indicates and
upwards or downwards movement of the parabola.
&quot;
• The vertical axis of symmetry is found at π₯ = − !#.
&quot;
b.
c.
&quot;!
• The vertex is found at (− !# ; π − \$#).
Factored form: π¦ = π(π₯ − π)(π₯ − π)
• a is a real number.
• p and q are the roots or x-intercepts.
Vertex form: π¦ = π(π₯ − β)! + π
• a is a real number.
• h is the x-coordinate of the vertex of the parabola.
• k is the y-coordinate of the vertex of the parabola.
FACTORING
1. Factor out any common factors using the distributive law.
For example, 3π₯ ! − 12π₯ + 12 = 3(π₯ ! − 4π₯ + 4).
2. Apply factoring formulas. For example, 3(π₯ ! − 4π₯ + 4) =
3(π₯ − 2)(π₯ − 2).
3. If no formulas can be applied, use the product-sum method
for 0 = ππ₯ ! + ππ₯ + π to find two factors of the form (dx+e)
and (mx+n) where the cross product of d*n + e*m = b, and
e*n = c.
4. If no factors can be found with the product-sum method, use
the quadratic formula to find the roots and apply the Factor
Theorem (if a polynomial has a zero factor at x = b, then it
must have a factor of (x – b).
−π &plusmn; √π! − 4ππ
π₯=
2π
The discriminant of a quadratic equation is π· = π! − 4ππ, and it may
be:
• D &lt; 0, if the equation has no real roots (in this case it has two
imaginary roots).
• D = 0, if the equation has one real root.
• D &gt; 0, if the equation has two distinct real roots.
Additionally, the sum of the roots of an equation is
&amp;
product of the roots of an equation is #.
%&quot;
#
Write 3π₯ ! + 11π₯ + 10 in factored form.
Write (π₯ + 3)(2π₯ − 5) in standard form.
Write 2(π₯ − 3)! − 5 in standard and factored forms.
Which of the following is a factor of π₯ ! + 8π₯ + 16?
a. π₯ − 4
b. π₯ − 8
c. π₯ + 4
d. π₯ + 8
Factorize 2π₯ ! − 18 using common factors and applying
factoring formulas.
Solve for x: 5π₯ ! + 10π₯ + 3 using the quadratic formula:
How many roots does 0.5π₯ ! + 4π₯ + 8 have? What is the
sum of its roots?
How many roots does 2π₯ ! + 8π₯ + 3 have? What is the
product of its roots?
, and the
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15
3.2
The graph of a quadratic expression will always be a parabola.
Depending on the form of the expression given, it is possible to use known values to graph the expression.
Graph 2π₯ ! + 8π₯ + 6.
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16
3.3
Higher order equations and operations
HIGHER ORDER POLYNOMIALS
Higher order polynomials are similar to quadratic expressions, but their
highest power is three or more.
What is the degree of (π₯ + 3)(π₯ − 5)(π₯ + 1)?
What is the degree of π₯ ! 3π₯ + 3π₯ + 10?
OPERATIONS WITH POLYNOMIALS
To add polynomials, identify the like terms (terms with the same exact
variables raised to the same exact power) and combine them.
(8π&quot; π# + 6π# π − 4π# + 5) + (10π# π − 4π&quot; π# + 6π# − 7)
(8π&quot; π# + 6π# π − 4π# + 5) − (10π# π − 4π&quot; π# + 6π# − 7)
MULTIPLICATION
To multiply polynomials, use distribution and multiply the coefficients of
terms and use the rules of exponents to find the exponents for each
variable.
(9π − ππ)(5π# π + 7ππ − π)
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17
3.3
Higher order equations and operations
DIVISION
• To divide monomials, divide the coefficients and then use
the rules of exponents to divide the variables.
• To divide a polynomial by a monomial, distribute the
monomial as denominator for each term of the polynomial
and divide as monomials.
• To divide two polynomials:
o Write each of them in descending order, and
complete missing terms with a coefficient of 0.
o Divide the terms with the highest powers and
multiply the answer by the divisor (the polynomial
you are dividing by).
o Subtract and bring down the next term.
o Repeat the process until there are no more terms
left.
o If there is a remainder, it must be written as a
11
(14π₯ &quot; π¦)/(28π₯ % π¦ \$ )
(4π₯ \$ π¦ &amp; − 2π₯ ' π¦ &quot; + 6π₯ &quot; π¦ # )/(2π₯ # π¦)
Use long division to divide (π₯ &quot; − 4π₯ # + 2π₯ − 3) ππ¦ (π₯ + 2).
Ruffini’s rule may be used when the divisor has the form (x – a). For
example, to divide (π₯ \$ − 16) by (π₯ + 2):
Use Ruffini’s rule to divide (π₯ &quot; − 4π₯ # + 2π₯ − 3) ππ¦ (π₯ + 2).
The Remainder Theorem calculates the remainder of a division when
the divisor has the form (x – a) by making (x – a) = 0, finding a, and
replacing the value in the polynomial. If y = 0, then there is no
remainder.
Use the Remainder Theorem to calculate the remainder of
(π₯ &quot; − 4π₯ # + 2π₯ − 3) /(π₯ + 2).
For an expression “x” to be a factor of another expression “y”, the
remainder of their division must be zero.
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18
3.4
THE LAWS OF EXPONENTIALS
1.
2.
3.
4.
5.
6.
7.
!
If n is a positive integer, π₯ means x multiplied by itself n times.
If n is a negative integer, π₯ ! means (1/x) multiplied by itself n times.
π₯ &quot; = 1.
π₯ # *π₯ ! = π₯ #\$!
π₯ # /π₯ ! = π₯ #%!
(π₯ # )! = π₯ #!
!
√π₯ # = π₯ #/!
'&quot;
If π − 3π = 6, which of the following is equivalent to ()# ?
a. 3*
+ '
b.
c.
d.
-,.
(3%( )(
3%*
\$
Which of the following is equal to 8%% ?
a. −2+
b.
− (%
+
c.
+&quot;
+
d.
!
1.
2.
√π₯ # = π₯ #/!
!
!
!
( 1π₯ )( 1π¦ ) = 1π₯π¦
3.
!
!
./
01
Which of the following is equivalent to
a.
b.
c.
d.
! /
= 31
• Factoring out perfect squares from the radicand.
• Multiplying top and bottom by the radical (in fractions).
• Multiplying top and bottom by the conjugate of the
denominator (if the denominator includes a sum or a
*Remember that expressions must only have radicals in the numerator
(never in the denominator). Therefore, you must rationalize your final
expressions using these methods.
(\$
(√(\$3√+4
√(
?
6√10
7
14
19
If π₯ ( = 4 and π¦ ( = 9, and if (π₯ − 2)(π¦ + 3) ≠ 0, what is the
value of x + y?
a. -5
b. -1
c. 1
d. 5
If
+
/\$(
= √2 , solve for x.
To solve exponential and radical equations, apply the laws of
exponentials and radicals to isolate the desired expression.
If
+
(&amp;
= 4√2 , solve for k.
+
%!
If - .
√/
!
= π¦ \$ , and π ≠ 0 , find x in terms of y.
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19
3.4
EXPONENTIAL FUNCTIONS
An exponential function with base b is defined by π(π₯) = ππ / + π,
where π ≠ 0, π &gt; 0, π ≠ 1, and x is any real number.
The effect of q:
• The line y = q is the horizontal asymptote (the number that
the function approaches but never reaches).
• For q &gt; 0, f(x) moves vertically upwards by q units.
• For q &lt; 0, f(x) moves vertically downwards by q units.
The effect of a and b:
• If b &gt; 1:
•
If 0 &lt; b &lt; 1:
•
If b ≤ 0, f(x) is not defined.
EXPONENTIAL GROWTH AND DECAY
•
In exponential growth and decay functions, the growth factor
in the exponential function (“b”) is replaced by (1 + r) or (1 – r):
o Exponential growth: π¦ = π(1 + π)/
o Exponential decay: π¦ = π(1 − π)/
• In these functions:
o a represents the initial value before measuring growth
• If b ≤ 0, f(x) is not defined.
or decay.
o r represents the growth or decay rate, and it is often
represented as a percentage and expressed as a
decimal.
o 1+r or 1-r represents the growth or decay factor.
o x represents the number of time intervals that have
passed.
Graph the function π¦ = 2(3)/ + 1 and identify:
• Value of q:
• Effect of q:
• Value of a:
• Effect of a:
• Value of b:
• Effect of b:
• Asymptote:
• Domain:
• Range:
In 2016, the population of Town X was estimated to be
35,000 people, with an annual rate of increase of 2.4%.
a. What is the growth factor for Town X?
b. Write an equation to model future growth.
c. Use the equation to estimate the population in 2020 to
the nearest hundred people.
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20
3.5
Rational Expressions
OPERATIONS WITH RATIONAL EXPRESSIONS
A rational expression is a fraction that has polynomials in both the
numerator and the denominator.
To add or subtract rational expressions, find a common denominator
and add or subtract like terms in the numerator.
To multiply rational expressions, multiply the numerators and the
denominators.
!
#
For !&quot;# − ! , which of the following is equivalent to the
expression for all positive values of x?
a.
b.
c.
d.
! ! \$!\$#
! ! &quot;!
! ! \$!&quot;#
! ! &quot;!
! ! \$#
! ! &quot;!
%
π₯ −1
To divide rational expressions, invert the second fraction and operate
as a multiplication.
SIMPLIFYING RATIONAL EXPRESSIONS
Rational expressions, such as complex fractions, can be simplified by
cancelling common factors or by multiplying top and bottom by a
convenient factor.
If π₯ = 3π and π ≠ 2 , which of the following is equivalent to
! ! \$&amp;'
a.
b.
c.
d.
SOLVING RATIONAL EQUATIONS
When solving equations that include fractions or rational expressions,
it may be useful to simplify the equation by multiplying both sides by
the common denominator.
(!\$')!
*&quot;%
?
*\$%
&amp;*&quot;%
&amp;*\$%
&amp;*&quot;%
&amp;*
+*! \$&amp;'
+&quot;&amp;'
#
#
If x &gt; 0 and !\$# − !&quot;# = 2, what is the value of x?
The function f is defined by the equation π(π₯) = π₯ % − 3π₯ −
18. If the function h is defined by the equation β(π₯) =
,(!)
, for what value of x does h(x) = 6?
%!\$#%
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21
3.6
Non-linear Expressions
PARENT FUNCTIONS
In order to understand how to manipulate non-linear expressions, it is essential to know the types of functions and equations that exist.
A parent function is defined as the simplest function that satisfies all requirements for a specific type of function.
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22
3.6
Non-linear Expressions
MANIPULATION OF NON-LINEAR EXPRESSIONS
To manipulate non-linear expressions, respect the order of operations
and use the properties you have learned so far.
!
Leaf’s Law states that πΏ = √2π₯ &quot;#!, where p represents price per
SAT book, q represents quantity of books purchased in bulk, and
x represents the number of years after 2016. What is p in terms
of L, q, and x?
For πΌ =
SOLVING NON-LINEAR SYSTEMS
When solving non-linear systems, you can use the same methods
used for linear systems: substitution, combination, and graphing.
However, if the system has equations of different degrees or forms,
it is better to use substitution instead of combination.
\$%
√'()
Find x and y if:
, find R in terms of P, T and I.
π¦ = π₯* − π₯
π¦ =π₯−1
11
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23
4.1
PART Iv: Geometry and Trigonometry
Angles and PArallel Lines
THE INTERSECTING LINES THEOREM
When two lines cross, the vertical angles that are formed are congruent
(they are the same), while the adjacent angles that are formed are
supplementary (their sum is 180 degrees).
If two lines cross forming angle A with a measure of 35&deg;, what
is the measure of angles B, C, and D?
C
A = 35&deg;
B
D
THE PARALLEL LINES THEOREM
When two parallel lines are crosses by a third line, they form either eight
right 90&deg; angles, or four acute angles and four obtuse angles, where:
a. All acute angles are congruent,
b. All obtuse angles are congruent,
c. And any acute angle is supplementary to any obtuse angle.
In the figure above, ABCD is a parallelogram, and point B lies
#### . If x = 40, what is the value of y?
on π΄πΈ
THE “ZCUF” ANGLES
When two parallel lines are crosses by a third line, and the diagram gets
too complicated, the “ZCUF” angles can be used.
If lines l and m are parallel in the figure above, what is the
value of x?
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24
4.2
PART Iv: Geometry and Trigonometry
Triangles
INTERIOR AND EXTERIOR ANGLES
•
In any triangle, the sum of the interior angles is 180&deg;.
Triangle ABC has three angles (A, B and C). If A measures 60&deg; and
B measures 90&deg;, what is the measure of C?
A
B
a + b + c = 180&deg;
•
In any triangle, if any side is extended, it makes an exterior
angle with the adjacent side. The measure of any exterior angle
equals the sum of the two remote interior angles.
C
If side BC was extended, what would the measure of exterior
angle C be?
SIDES AND ANGLES
• Side-Angle Theorem: The biggest interior angle in a triangle will
always be opposite the biggest side, and the smallest interior
angle will always be opposite the smallest side.
In the figure above, point D is on side AC of triangle ABC. If AD =
DB = DC, what is the value of x + y?
•
Types of triangles based on the length of the sides:
o Equilateral: All three sides have the same measure, and
consequently all three internal angles have the same
measure.
o Isosceles: Two sides have the same measure and two angles
have the same measure. According to the Isosceles Triangle
Theorem, the two congruent angles will always be opposite
the two congruent sides.
o Scalene: All sides and all angles have different measures.
THE TRIANGLE INEQUALITY
The sum of any two sides of a triangle must always be greater than the third side.
Therefore, the length of any side must be between the sum and the difference of the
other two sides.
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25
4.2
PART Iv: Geometry and Trigonometry
Triangles
CONGRUENCE AND SIMILARITY
•
•
•
•
•
•
•
•
Congruence means that two figures have the same shape and size.
Similarity means that two figures have the same shape but not the
same size.
If two figures are similar, all corresponding angles are congruent,
and all corresponding sides are proportional.
Dilation is a technique used to create similar triangles, where each
point is stretched outwards from the center point by multiplying
distances by the scale factor.
The Angle-Angle (AA) Theorem: If two triangles have two
congruent pairs of corresponding angles, then the triangles are
similar, and all corresponding sides are proportional.
Perimeters: If two similar polygons have corresponding sides in a
ratio of a:b, then their perimeters have a ratio of a:b.
Areas: If two similar polygons have corresponding sides in a ratio
of a:b, then their areas have a ratio of a2:b2.
Volumes: If two similar solids have corresponding sides in a ratio of
a:b, then their volumes have a ratio of a3:b3.
#### and ####
In the figure above, π΄π΅
πΆπ· are line segments that
intersect at point P. What is the value of m?
If two triangles have corresponding sides in a ratio of 1:2,
what is the ratio of their perimeters, areas and volumes?
THE PITHAGOREAN THEOREM
•
•
The Pythagorean Theorem: If a, b and c are the lengths of the sides
of a right triangle, where c is the longest side, then π! + π! = π ! .
Special Right Triangles:
What is the perimeter of quadrilateral ABCD in the figure
above?
•
The Distance Formula: The Pythagorean Theorem can be used to
calculate distance:
o In two dimensions:
π = ,(ππ − ππ )π + (ππ − ππ )π
o
In three dimensions:
π = ,(ππ − ππ )π + (ππ − ππ )π + (ππ − ππ )π
AREA
• The area of any triangle can be calculated by multiplying its
base by its height and dividing the product by two.
π∗π
π¨=
π
• The area of an equilateral triangle can be calculated using the
length of its side:
√π π
π¨=
π
π
The figure above shows a rectangular box with a length of
24, a width of 10, and a height of x. If AB = √712 , what is
the volume of the box in cubic units?
If the sides of an equilateral triangle measure 2 cm, use both
formulas to calculate the area.
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26
4.3
PART Iv: Geometry and Trigonometry
Circles
EQUATIONS
Since a circle is defined as the set of all points in a plane that are at a
fixed distance r from the center (h, k), the Pythagorean Theorem can
be used to find the equation of the circle:
(π₯ − β)! + (π¦ − π)! = π !
Which of the following equations represents a circle in the xyplane that passes through the point (1, 5) and has a center of
(3, 2)?
a. (π₯ − 3)! + (π¦ − 2)! = √13
b. (π₯ − 3)! + (π¦ − 2)! = 13
c. (π₯ − 1)! + (π¦ − 5)! = 13
d. (π₯ − 3)! + (π¦ − 2)! = 25
CIRCUMFERENCE AND AREA
•
Circumference: Since π is defined as the ratio of the
circumference of any circle to its diameter,
πΆππππ’ππππππππ πΆππππ’ππππππππ
π=
=
π·πππππ‘ππ
2π
What is the area, in square centimeters, of a circle with a
circumference of 16π centimeters?
πΆππππ’ππππππππ = 2ππ
•
Area: If a circle is cut into tiny sectors and rearranged as
shown, a parallelogram-like shape with a height of r and a
length of half the circumference is created. Since the area of a
parallelogram equals its base time its height,
π΄ = (ππ)(π) = ππ !
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27
4.3
PART Iv: Geometry and Trigonometry
Circles
TANGENTS TO A CIRCLE
A line is tangent to a curve if it touches the curve at only one point and
is perpendicular to the radius at the point of tangency.
In the figure below, AAAAA
ππ is tangent to the circle at point P,
ππ = √269, and ππ = √244. If the circle has an area of
100π, what is the area of triangle MOQ?
A radian is a unit for measuring angles, and it represents the ratio of an
&quot;#\$
For 360&deg;, since πππππ’ππππππππ = 2π, πππππππ  = #&quot;%&amp;'( =
!)#
#
What is the degree measure of an angle that measures 4.5
= 2π.
CHORDS
A chord is a line segment that connects two points on a circle. The
perpendicular segment from the center of the circle to a chord will
always bisect the chord.
The circle above has an area of 100π square centimeters. If
AAAA from the center of the circle?
AB = 8, how far is π΄π΅
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28
4.3
PART Iv: Geometry and Trigonometry
Circles
ARCS
An arc is a portion of a circumference that has a corresponding central
angle. The ratio of an arc length to the circumference equals the ratio
of its central angle to 360&deg;.
ππ΄π΅
π₯
=
2ππ
360
*Not to scale.
In the figure below, AC is a diameter of the circle with center O,
OB = 12, and the length of arc AB is 7π. What is the value of x?
A minor arc is less than 180&deg; and is equal to the central angle. A major
arc is greater than 180&deg;. Minor arcs are named with two letters (its
endpoints), and major arcs are named with three letters (its endpoint
and any other point in between).
SECTORS
A sector is a “pie slice” of a circle. The ratio of a sector area to the
area of the circle is equal to the radio of its central angle to 360&deg;.
π΄πππ ππ π πππ‘ππ
π₯
=
!
ππ
360
INSCRIBED AND CIRCUMSCRIBED ANGLES AND POLYGONS
•
Inscribed vs. circumscribed:
Inscribed
•
*Not to scale.
In the figure below, AC is a diameter of the circle with center O
and OB = 7. If the measure of ACB is 20&deg;, what is the area of the
The measure of the inscribed angle ACD is x, and the measure of
the central angle CAB is y. Find CAB in terms of x.
Circumscribed
Inscribed Angle Theorems:
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29
4.4
PART Iv: Geometry and Trigonometry
PERIMETERS, Areas, and Volumes
BASIC FORMULAS
Right rectangular
prism
Right circular
cylinder
Sphere
Right circular cone
Rectangular pyramid
What is the area, in square units, of the triangle?
THE STRANGE AREA RULE
If you need to find the area of a figure that does not have a fixed formula,
think of the area as the sum of simpler shapes.
What is the area, in square units, of the quadrilateral?
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30
PART Iv: Geometry and Trigonometry
4.5
Trigonometry
TRIGONOMETRIC FUNCTIONS (SOH CAH TOA)
In the triangle below, x represents the measure in radians of
the smallest angle. What is the tangent of 2x?
QII
Students
Sin and cosec
positive
Take
Tan and cot
positive
a.
QI
All
b.
All positive
c.
d.
Calculus
√(
(
√'
'
√'
(
√3
Cos and sec
positive
QIII
QIV
When working with trigonometric functions, the lengths of the sides
are not necessarily the same as expressed by the trigonometric
function, as this could be a simplified ratio. Side lengths are always
proportional to the values of the functions.
If sin x = 4/5 and BC = 9, what is the length of AC?
A
x
B
UNIT CIRCLE
C
!
!
Which of the following is equivalent to πππ  &quot; − π ππ # ?
a.
b.
c.
d.
\$%√'
(
√(%√'
(
√(%\$
(
√'%√(
(
For any ordered pair (x;y), πππ Θ = x and π ππΘ = y.
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SCORE – Test Prep and College Counseling. This document may not be distributed or reproduced
without the express written consent of its authors.
31
4.5
PART Iv: Geometry and Trigonometry
Trigonometry
THE PYTHAGOREAN IDENTITY
For all values of x, π ππ( π₯ + πππ  ( π₯ = 1.
!
If ( &lt; π₯ &lt; π and sin x = 0.8, what is the value of cos x?
According to the Pythagorean Theorem,
(πππππ ππ‘π)( + (ππππππππ‘)( = (βπ¦πππ‘πππ’π π)(
If both sides are divided by (βπ¦πππ‘πππ’π π)( ,
πππππ ππ‘π (
ππππππππ‘ (
βπ¦πππ‘πππ’π π (
(
) +(
) =(
)
βπ¦πππ‘πππ’π π
βπ¦πππ‘πππ’π π
βπ¦πππ‘πππ’π π
Which is equivalent to:
π ππ( π₯ + πππ  ( π₯ = 1.
COMPLEMENTARY ANGLES
The two acute angles in a right triangle are always complements of one
another (their sum is 90&deg; or π/2 radians). If one angle measures x, the
other measures π/2 – x.
If sin x = a and x + y = π/2, what is the value of sin y?
a. π
b. 1 − π(
c. √1 − π
d. √1 − π(
As a result, the sine of an angle equals the cosine of its complement,
and the cosine of an angle equals the sine of its complement.
π ππ =
π
− π₯@ = cos π₯
2
πππ  =
π
− π₯@ = sin π₯
2
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SCORE – Test Prep and College Counseling. This document may not be distributed or reproduced
without the express written consent of its authors.
32
5.1
PART v: TIPS AND STRATEGY
Graphing AND SCIENTIFIC Calculator
RECOMMENDED CALCULATORS
As in most standardized examinations, you will only be allowed to use
one calculator. Therefore, you must be familiar with the calculator you
choose to bring on test day.
The best option is to use a graphing calculator. However, if you don’t
have one, you can use a scientific calculator with equation-solving
functions. If your calculator does not have this option, you will be at a
disadvantage during the exam. If you decide to borrow a calculator from
a friend, make sure to get it with anticipation so that you can learn how
to use it.
SCORE recommends the Casio fx-CG50 graphing calculator (USD 90 on
Amazon) or the Casio fx-991LAX scientific calculator (S/. 100 in Tailoy).
If you have another calculator, make sure to check the list of acceptable
WHEN TO USE THE CALCULATOR
The SAT has two math sections:
• Section 3: Math – No Calculator
• Section 4: Math – Calculator
Even though a calculator is allowed for all questions in section 4, not all questions can be answered using it. Many questions can only be
solved without a calculator. Make sure to read each question carefully before deciding to use your calculator.
Read the following questions and decide whether you would solve it manually (M) or with your calculator (C).
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SCORE – Test Prep and College Counseling. This document may not be distributed or reproduced
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33
PART v: TIPS AND STRATEGY
5.1
Graphing AND SCIENTIFIC Calculator
The graphing calculator has 20 different menu options. To perform well
in the SAT, you must know how to use 4 functions:
Run-Matrix: Arithmetic calculations.
Statistics: Regression (to find equations from a table of values).
Graph: Graphs of functions and equations.
Equation: Systems of equations and polynomial equations.
RUN-MATRIX
Use this option to perform arithmetic calculations (addition, subtraction, multiplication, division).
Battery status
Choose “Deg” for Angle.
Activates options in yellow
Activates options in red
Fractions
Exponents
Fraction/Decimal
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SCORE – Test Prep and College Counseling. This document may not be distributed or reproduced
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34
PART v: TIPS AND STRATEGY
5.1
Graphing AND SCIENTIFIC Calculator
STATISTICS
Use this function to find equations from a table of values.
GRAPH
Use this function to graph functions and equations, and to solve non-linear systems of equations or inequalities.
Press EXE
Press SHIFT
Vz
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SCORE – Test Prep and College Counseling. This document may not be distributed or reproduced
without the express written consent of its authors.
35
5.1
PART v: TIPS AND STRATEGY
Graphing AND SCIENTIFIC Calculator
Press SHIFT
Press EXE
ZOOM
Press EXE
Use arrows to
move around
Press SHIFT
TRACE
Press SHIFT
G-SOLVE
TYPE
*Choose type before inserting the function.
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SCORE – Test Prep and College Counseling. This document may not be distributed or reproduced
without the express written consent of its authors.
36
5.1
PART v: TIPS AND STRATEGY
Graphing AND SCIENTIFIC Calculator
EQUATION
Use this function solve systems of equations, polynomial equations, and other equations.
SIMULTANEOUS
POLYNOMIAL
SOLVER
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37
PART v: TIPS AND STRATEGY
5.2
CHEAT SHEET
PART I: HEART OF ALGEBRA
FACTORING IDENTITIES:
(π + π)! = (π + π)(π + π) = π ! + 2ππ + π !
•
(π − π)! = (π − π)(π − π) = π ! − 2ππ + π !
•
(π + π)(π − π) = π ! − π !
•
LINEAR EQUATIONS:
Linear form
Slope-intercept
Standard
Point-slope
Intercept
ROUNDING:
b.
c.
0.00001
Y-intercept
b
c/b
b
X-intercept
a
(! )(&quot;
Slope formula: π ππππ =
•
Slope interpretation:
o
Positive slope: The line goes up as you move to the right.
o
Negative slope: The line goes down as you move to the right.
o
Zero slope: The line is horizontal.
o
Undefined slope: The line is vertical.
o
Parallel slopes have equal values: π+ = π!
+
o
Perpendicular slopes are opposite and reciprocal: π+ = −
•
•
Distance between two points on a line: /(π₯+ − π₯! )! + (π¦+ − π¦! )!
* -* ( -(
Midpoint: ( &quot; ! ; &quot; !)
&quot;&amp;'
=
*! )*&quot;
,!
LINEAR SYSTEMS:
a.
&quot;#\$%
Slope
m
-a/b
m
-
•
0.000001
Millionths
Hundred-Thousandths
0.001
0.0001
Thousandths
Ten-Thousandths
0.1
0.01
Hundredths
.
Tenths
1
Decimal Point
10
Ones
100
DECIMAL PART
Tens
1,000
Hundreds
10,000
Thousands
100,000
Ten Thousands
1,000,000
Hundred Thousands
Millions
WHOLE PART
Equation
y = mx + b
ax + by = c
y - y1 = m(x - x 1)
x / a+y / b =1
No solution: The equations do not intersect. In the case of linear
systems, the lines are parallel. Equal slopes, different yintercepts.
Infinite solutions: The equations lie on the same line, so they are
coincidental. Equal slopes, same y-intercept.
One solution: The lines intersect at one point. Different slopes,
y-intercept may be the same or different.
!
!
INEQUALITIES:
•
If you multiply or divide both sides by a negative number, you must switch the direction
of the inequality.
•
Systems of inequalities must be solved by graphing.
PART II: Problem Solving and Data Analysis
PERCENTAGES:
DATA ANALYSIS:
•
π΄π£πππππ =
.&amp;, 01 '&amp;,2%&quot;\$
# 01 '&amp;,2%&quot;\$
•
# 01 '&amp;,2%&quot;\$-+
•
ππππππ π‘πππ (πππ ππ’ππππ ππ π‘ππππ ) =
•
Standard deviation: The average distance of each element from
the mean. The more spread out the data is on a graph, the larger
the standard deviation.
!
•
CHANGING BY PERCENTAGES:
o
To increase a number by a%, multiply by (100 + a)% or by (1 + a%).
o
To decrease a number by a%, multiply by (100 – a)% or by (1 – a%).
PERCENT CHANGE: To find a percent change, use the following formula:
πππππ ππππππ − ππππππππ ππππππ
%ππππππ =
∗ πππ
ππππππππ ππππππ
ARRANGEMENTS:
•
•
ARRANGEMENTS: Arrangements are used to determine how many arrangements of something are possible. For items of different categories, the number of options in
each category are multiplied.
FACTORIALS: The factorial of n is the number of ways in which the n elements of a group can be ordered. It is expressed as n!, where n! = 1 * 2 * … * (n – 2) * (n – 1) * n.
PART III: Passport to Advanced Math
TRANSFORMATION OF FUNCTIONS:
•
•
•
•
Movement in the x-axis:
o
To the right: π(π₯ − 1)
o
To the left: π(π₯ + 1)
Movement in the y-axis:
o
Upwards: π(π₯) + 1
o
Downwards: π(π₯) − 1
Reflection over an axis:
o
Over the x-axis: -π(π₯)
o
Over the y-axis: π(−π₯)
Stretching and shrinking:
o
Vertical stretch: ππ(π₯), when k &gt; 1
o
Vertical shrink: ππ(π₯), when k &lt; 1
RUFFINI’S RULE AND REMAINDER THEOREM:
•
Ruffini’s rule may be used when the divisor has the form (x – a) (for
example, to divide (π₯ 5 − 16) by (π₯ + 2)).
•
The Remainder Theorem calculates the remainder of a division
when the divisor has the form (x – a) by making (x – a) = 0, finding
a, and replacing the value in the polynomial. If y = 0, then there is
no remainder.
•
Standard form: π¦ = ππ₯ ! + ππ₯ + π, where:
o
a determines the orientation and width of the parabola:
&sect;
If a positive, the parabola opens upwards.
&sect;
If a is negative, the parabola opens downwards.
&sect;
An increasing a narrows the parabola.
&sect;
A decreasing a widens the parabola.
o
b indicates the slope of the parabola at the y-intercept.
o
c indicates the y-intercept (0;c) and indicates and upwards or downwards
movement of the parabola.
2
o
The vertical axis of symmetry is found at π₯ = − .
o
•
•
The vertex is found at (−
2
!4
;π −
2!
54
!4
).
Factored form: π¦ = π(π₯ − π)(π₯ − π)
o
a is a real number.
o
p and q are the roots or x-intercepts.
Vertex form: π¦ = π(π₯ − β)! + π
o
a is a real number.
o
h is the x-coordinate of the vertex of the parabola.
o
k is the y-coordinate of the vertex of the parabola.
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SCORE – Test Prep and College Counseling. This document may not be distributed or reproduced
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38
5.2
PART v: TIPS AND STRATEGY
CHEAT SHEET
•
−π &plusmn; √π ! − 4ππ
π₯=
2π
•
The discriminant of a quadratic equation is π· = π ! − 4ππ, and it
may be:
o
D &lt; 0, if the equation has no real roots (in this case it has
two imaginary roots).
o
D = 0, if the equation has one real root.
o
D &gt; 0, if the equation has two distinct real roots.
)2
Sum of the roots of an equation:
•
Product of the roots of an equation:
•
4
6
4
LAWS OF EXPONENTS:
•
If n is a positive integer, π₯ ' means x multiplied by itself n times.
•
If n is a negative integer, π₯ ' means (1/x) multiplied by itself n times.
•
π₯ 7 = 1.
•
π₯ , *π₯ ' = π₯ ,-'
•
π₯ , /π₯ ' = π₯ ,)'
•
(π₯ , )' = π₯ ,'
#
•
√π₯ , = π₯ ,/'
#
•
√π₯ , = π₯ ,/'
#
#
#
•
( /π₯ )( /π¦ ) = /π₯π¦
•
EXPONENTIAL FUNCTIONS:
•
An exponential function with base b is defined by π(π₯) = ππ * +
π, where π ≠ 0, π &gt; 0, π ≠ 1, and x is any real number.
•
The effect of q: The line y = q is the horizontal asymptote (the
number that the function approaches but never reaches).
•
For q &gt; 0, f(x) moves vertically upwards by q units.
•
For q &lt; 0, f(x) moves vertically downwards by q units.
•
The effect of a and b:
o
If b &gt; 1:
#
9*
#
:(
#
*
= a
(
•
o
Factoring out perfect squares from the radicand.
o
Multiplying top and bottom by the radical (in fractions).
o
Multiplying top and bottom by the conjugate of the denominator (if the denominator
includes a sum or a difference with radicals).
•
Remember that expressions must only have radicals in the numerator (never in the
denominator). Therefore, you must rationalize your final expressions using these methods.
GRAPHING FUNCTIONS:
o
If 0 &lt; b &lt; 1:
o
If b ≤ 0, f(x) is not defined.
EXPONENTIAL GROWTH AND DECAY:
•
In exponential growth and decay functions, the growth factor in
the exponential function (“b”) is replaced by (1 + r) or (1 – r):
o
Exponential growth: π¦ = π(1 + π)*
o
Exponential decay: π¦ = π(1 − π) *
•
In these functions:
o
a represents the initial value before measuring growth
or decay.
o
r represents the growth or decay rate, and it is often
1.
If b ≤ represented
0, f(x) is not defined.
as a percentage and expressed as a
decimal.
o
1+r or 1-r represents the growth or decay factor.
o
x represents the number of time intervals that have
passed.
INTERSECTING LINES THEOREM:
PARALLEL LINES THEOREM:
“ZCUF” ANGLES:
C
This document has been created for educational purposes only and meant to be used exclusively by
SCORE – Test Prep and College Counseling. This document may not be distributed or reproduced
without the express written consent of its authors.
39
5.2
PART v: TIPS AND STRATEGY
CHEAT SHEET
INTERIOR ANGLES:
EXTERIOR ANGLES:
CONGRUENCE AND SIMILARITY:
CONGRUENCE:
•
Congruence means that two figures have the same shape and size.
SIMILARITY:
•
Similarity means that two figures have the same shape but not the
same size.
•
If two figures are similar, all corresponding angles are congruent,
and all corresponding sides are proportional.
The Angle-Angle (AA) Theorem: If two triangles have two congruent
•
pairs of corresponding angles, then the triangles are similar, and all
corresponding sides are proportional.
•
Ratios: If two similar polygons have corresponding sides in a ratio of
a:b, then:
Perimeters: a:b
o
Areas: a2:b2
o
Volumes: a3:b3
o
AREA OF A TRIANGLE:
•
•
The area of any triangle can be calculated by multiplying its base by
its height and dividing the product by two.
π∗π
π¨=
π
The area of an equilateral triangle can be calculated using the length
of its side:
√π π
π¨=
π
π
CIRCLES:
Equation: (π₯ − β)! + (π¦ − π)! = π ! , where:
•
o
h is the x-coordinate of the center of the circle.
o
k is the y-coordinate of the center of the circle.
o
r is the radius of the circle.
Circumference: πΆππππ’ππππππππ = 2ππ
•
Area: π΄πππ = ππ !
•
Units: 360&deg; = 2π πππππππ
•
TRIANGLE INEQUALITY:
SIDE-ANGLE THEOREM:
THE PITHAGOREAN THEOREM:
The Pythagorean Theorem: If a, b and c are the lengths of the sides of a right
•
triangle, where c is the longest side, then π ! + π ! = π ! .
Special Right Triangles:
•
•
The Distance Formula: The Pythagorean Theorem can be used to calculate distance:
In two dimensions:
o
π = /(ππ − ππ )π + (ππ − ππ )π
In three dimensions:
o
π = /(ππ − ππ )π + (ππ − ππ )π + (ππ − ππ )π
CHORD:
TANGENT TO A CIRCLE:
SECTOR:
ARC:
INSCRIBED AND CIRCUMSCRIBED ANGLE THEOREM:
π΄πππ ππ π πππ‘ππ
π₯
=
ππ !
360
ππ΄π΅
π₯
=
2ππ
360
INSCRIBED AND CIRCUMSCRIBED ANGLES AND POLYGONS:
Inscribed
Circumscribed
This document has been created for educational purposes only and meant to be used exclusively by
SCORE – Test Prep and College Counseling. This document may not be distributed or reproduced
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40
5.2
PART v: TIPS AND STRATEGY
CHEAT SHEET
Right rectangular
prism
Sphere
Right circular
cylinder
Right circular cone
Rectangular pyramid
TRIGONOMETRIC FUNCTIONS (SOH CAH TOA):
VALUE OF SINE AND COSINE:
For any ordered pair (x;y), πππ Θ = x and π ππΘ = y.
QII
Students
Sin and cosec
positive
Take
Tan and cot
positive
All positive
Calculus
Cos and sec
positive
QIII
COMPLEMENTARY ANGLES:
QI
All
QIV
THE PYTHAGOREAN IDENTITY:
π ππ s
π
− π₯t = cos π₯
2
πππ  s
π
− π₯t = sin π₯
2
This document has been created for educational purposes only and meant to be used exclusively by
SCORE – Test Prep and College Counseling. This document may not be distributed or reproduced
without the express written consent of its authors.
π ππ! π₯ + πππ  ! π₯ = 1.
41
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