PRESENTER: GLENROY PINNOCK MSc. Applied Mathematics; Marine
Engineering Diploma; Mathemusician; PhD. (EDUC)pending
JANUARY 14TH, 2011
1
What is a radical quantity in mathematics? E.g.,√a
Factor for algebraic expression:x 2 - y 2
LAWS OF INDICES
(RECALL SIX (6) OF THEM)
Rationalize 1
2 + √a
Factors for algebraic expressions:x 2 + y 2 , x 3 - y 3 , x 3 + y 3 , x 4 - y 4 , x 4 + y 4
2
(a + b) 0
(a + b) 1
(a + b) 2
(a + b) 3
(a + b) 4
(a + b) 5
1
1 1
1 2 1
1 3 3 1
1 4 6 4 1
1 5 10 10 5 1
3
y = ax 2 + bx + c
What is the discriminant to the formula on the left? Clearly, it’s b 2 - 4ac.
The solution x = -b+√ (b 2 - 4ac)
2a
What happens if this term is negative?
Recall that if the roots of the above quadratic equation is and β.
α
What is the sum of the roots and the product of the roots?
Write down the equation, whose roots are α 3 and β 3 ?
So, we can now discuss the significance of the discriminant.
a. The roots of a quadratic equation are imaginary/complex, if the discriminant is negative.
b. If the discriminant is greater than 0, then the roots are real.
c.
If b 2 = 4ac, then the roots are real and equal.
d. By the way, notice that these roots are basically the solutions of a quadratic equation.
PROVE THIS FORMULA!
4
sine θ = 0.5
Clearly sine θ = ½
Do you remember trig-ratios?
Do you recall the quadrant system?
What does that equation mean for the positive 0.5?
What happens if 0.5 is negative?
Solve:sine 2θ = 0.5, sine 3θ = 0.5
WOW!
What is the difference for the number of solutions, for the equations above?
Solve: sine 2 2θ = 0.25
We are ultimately breaking down
2 nd degree trig equations into a 1 st degree equation or factor.
5
2
4 9
- 8
1
This can be written as
9 = 2 (4) + 1.
Conceptually, we can say 9 represents a polynomial, 2 is the quotient, 4 is the divisor, and 1 is the remainder.
Let us now divide x 2 – 1 by x + 1.
Clearly, x 2 – 1≡ Q (x + 1) + 0.
How did I get a zero?
So, generally speaking
P (x) ≡ Q (x + a) + R.
NB: It is advisable to represent a remainder theorem/factor theorem problem in this format.
Remember to use the synthetic rule to reduce tedious long division. Also, you need to know how to solve a pair of simultaneous equations.
6
Always recall the laws of indices and indicial equations whenever you are doing log problems.
What is the logarithm of a number?
Now consider log
10
10 = ?
10 1 = 10
Similarly, log e
100 = y.
Clearly, e y = 100.
Now we can say it’s the definition of a logarithmic quantity.
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What is the difference between a horizontal line & a slanted line?
Let’s consider the slanted line:
B (x
1
, y
1
)
A (x
2
, y
2
)
What is the gradient of AB?
Clearly, grad AB = y
1 x
1
- y
- x
2
2
Two parallel lines will have equalgradients.
When one line is perpendicular to another, the product of their gradients is -1.
Consider the points A(2, 3) and
B(-1, -2). What is the equation of the line?
Recall y = mx + c
*c is the y intercept and m is the gradient.
Also, the gradient of a straight line is also equal to the tangent of inclination (tanθ) of the slanted line.
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h
area of a right-angled triangle
Construct a parallelogram from the points given above, and also find the area of the figure. Prove that the parallel sides of the parallelogram have equal gradients.
A = ½ bh
Construct a rhombus with points of your choice, and find the area of the rhombus.
Prove that the diagonal of the rhombus intersects at 90 0 .
b
Area of a non-right angled triangle
A= ½ ab sin C
This equation also can be written in two other forms. What are these forms?
NB: The coordinates for the point of intersection of two lines is basically the solution of two simultaneous equations.
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the multiplication law and the addition law
cumulativefrequency curve (OGIVE)
upper quartile, lower quartile, median, inter-quartile range, semiinter quartile range
percentiles
frequency polygon
permutation & combination
probability distribution
Poisson distribution
binomial distribution
orientation of the sample space diagram
normal distribution
10
Recall gradient (grad) of a straight line:
AB = y x
1
1
-y
-x
2
2
Remember that this represents a straight line.
Concept of a limiting value.
In the case of a curve, the gradient is found by considering the differential expression, namely, dy , f
׳
, f x dx
0
So, what is your interpretation of the limiting value?
δ y
δ y
δ x
δ x
As a novice, we can say dy ≡ δ y dx δ x
As δ x 0 that is the time dy = δ y dx δ x
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DISCUSSION
differentiation by first principles
differentiation of a product
differentiation of a quotient
differentiation of trigonometrical expressions
implicit differentiation
differentiation by approximation
differentiation express by rate of change
Clearly dy represents the gradient dx which is the tangent of the angle of inclination.
Differentiation by formula y = x n
∴
= nx n-1
Differentiate this equation: y = x 3 – x -2 + x 4
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B
A
The area under the line AB is ?
B
A
However, the area under the curved AB is found by integration.
Let us consider this curve to be y = x 2 for x ≥ 0.
The area under the curve is ydx.
On the other hand, the volume under the curve is y 2 dx, if the revolution is done about the x axis through 360 0
What would be the formula for the volume of revolution about the y axis?
13
Integration is considered to be anti-differentiation
(anti-derivative)
Given that y = x 2 dy= 2x dx
So, the integral of 2x can be written as 2x
By considering the formula dy= x n dx
∴ y = x n+1 n + 1
Clearly, 2x .dx = x 2
Finally, we can now say integration is to find y whenever dy dx
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DISCUSSION
Integration of a binomial expression to the n power
Integration of a trigonometric function
Integration by parts
IN A NUTSHELL THE INTEGRAL SYMBOL REPRESENTS SIGMA
NOTATION IN INTEGRATION THEORY.
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