Math I: Unit 3
Name:_______________________________________
FUNCTION: Each element of the domain is paired with exactly one element of the range
• In your own words, ---“For every x there is only one y”
FUNCTION NOTATION: Function Name(variable used in equation)
• Equations that are functions can be written in a form called function notation.
Equation
y = 3x – 8
Coordinate: (x, y)
•
Function Notation


f(x) = 3x – 8
Coordinate: (x, f(x))
f(x) read as “f of x” is three times x minus eight.
• In a function, x represents the elements of the domain, and f(x) represents the elements of
the range.
• Evaluating a function notation statement means _____________________________ the
value or expression in parenthesis for variable (x) in the function.
h(x) = 7 – 2x
g(x) = 2x2 + 5x – 9
Function is called ________
Variable used is ________
Function is called ________
Variable used is ________
________ = Domain values
________ = Range values
________ = Domain values
________ = Range values
______________ = Point
______________ = Point
Interpret the following function notation statements:
Example 1: f(3)  Substitute 3 for every x variable in the equation
Example 2: g(x) = 3  The function g has a value of 3 with what x-values
Example 3: h(2) = 3  The function h has a value of 3 when you substitute 2 for x in the equation.
1) g(4)
4) h(-3) = 13
2) f(2) = -2
5) g(x) = 19
3) h(x) = -1
6) f(-2)
FIND VALUES WITH FUNCTION NOTATION
1) If
f ( x )  2 x  5 find each value.
a. f(-2)
b. f(3)
c. f(1)
d. f(-5)
2) If g ( x )  3 x  7 find each value.
a. g(-2)
b. g(5)
c. g(0)
d. g(2y)
c. 3 h(1)
d. h(2) + 5
c. h(0) + 4
d. h(– 2)
c. g(1) – 4
d. 2 g(-4)
3) If h( x )  11  4 x find each value.
a. h(2)
b. h(-3)
4) If h(z) = z2 + 3z – 4 , find each value.
a. h(-4)
b. h(1)
5) If g(y) = y2 – 4y +2, find each value.
a. g(3)
b. g(-2)
6) The cost of yogurt is based on its weight in ounces by the formula C(w) = 1.40 + .30w.
a. How much does 3 ounces of yogurt cost?
b. How much does 8 ounces of yogurt cost?
7) A test grade is related to the number of hours studied by the formula T(h) = 53 + 4h.
a. What is your grade if you studied 7 hours?
b. What is your grade if you never studied?
8) If
f ( x )  2 x  5 , then determine x such that…
a. f(x) = 9
9) If
b. f(x) = - 1
g ( x )  9  3 x , then determine x such that…
a. g(x) = 12
b. g(x) = -0
10) Consider the function h(x) graphed below to answer the following questions
a. Find h(2)
b. Find h(-4)
c. Find h(4)
d. Find h(x) = - 4
e. Find h(x) = 4