Complete the square to find the vertex of each quadratic function. State the vertex. (10 marks)
A) f(x) = x2 + 8x – 3
B) f(x) = x2 – 5x + 8
C) f(x) = 2x2 – 12x + 1
D) f(x) = 3x2 + 2x – 5
I will do one, you do the others.
You will learn how to do these only by doing lots of them
c)
f(x) = 2x^2 - 12x + 1
= 2(x^2 - 6x + ..... ) + 1
= 2(x^2 - 6x + 9 - 9 ) + 1
= 2( (x-3)^2 - 9) + 1
= 2(x-3)^2 - 18 + 1
= 2(x-3)^2 - 17
vertex is (3, -17)