## Wednesday, 6 February 2013

### Lesson Summary 7/2/13 Shaun Ng

Level Test

Elementary math

Duration: 45 mins
30 marks

Topics:
1. Algebraic manipulation
• Factorisation
• Expansion
1. Algebraic Fraction
3  Indices (no surds + logs) (quiz c)
1. Quadratic Function/graph plotting  (U shaped and n shaped)

Additional math

Duration: 45 mins
30 marks

Topics:
1. Polynomials
2. Remainder Factor Theorem
3. Cubic expression/equation
4. Partial fraction
(All Jumbled up)
(Start doing Exam Prep Questions)

Question for fun

Given that the roots of a quadratic function is -3 and 1. Find the function if x=-3 (x+3)=0

1. Case 1
the coefficient of x^2 is 2     (3)

1. Case 2
y intercept is -6.              (3)

Sketch the above function(s), showing clearly the x and y intercepts, and the turning point. State also the nature of turning point. (2)

y = f(x) = ax^2+bx+c
= A(x+d)(x+e)
= A(x_3)(x-1)
= A(x^2+2x-3)
=Ax^2+2Ax-3A

1. f(x) = 2(x+3)(x-1)
= 2x^2+4x+6

1. f(x) = A(x+3)(x-6)
x=0, f(0) = A(3)(-1) = -6
A = 2
Hence, f(x) = 2(x+3)(x-1)
= 2x^2+4x-6

Nature of turning point = Minimum tp
Turning point = Two x intercepts added/2
Sub x value into answer for a.]]]