Question

Which of the following is the graph of the quadratic function y=x^2 - 4x + 4?

Answer 1

D

Explanation:

convert into vertex form

x^2-4x+4 = (x-2)^2 +0

vertex: (2, 0)

Graph D has vertex (2, 0)

Answer 2

look at x=0 and plug in 0 for any x you find in the equation

f(0) = 0² - 4*0 +4 = 4

c is out of the race then

let's do this again, but test for x=1 and x=2

f(1) = 1² - 4*1 + 4 = 1

f(2) = 2² - 4*2 +4 = 0

a and b are out

its graph d

when testing like this, choose easy-to-calculate numbers to find out what points you get when asking for the y-value at an arbitrary x-place