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.]]]

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