Question

Which values for h and k are used to write the function f of x = x squared + 12 x + 6 in vertex form?

h=6, k=36
h=−6, k=−36
h=6, k=30
h=−6, k=−30

Answer 1

Complete the square:

f(x) = x^2 + 12x + 6
= (x^2 + 12x + 36) + 6 − 36
= (x + 6)^2 − 30

So in f(x) = (x − h)^2 + k, h = −6 and k = −30.