Question

Given f (x) = x2 + 10x + 28 in standard form, convert to vertex form using completing the square. Show work to receive credit. (20 points)

Answer 1

f(x) = (x + 5)² + 3

Explanation:

f(x) = x² + 10x + 28

to complete the square

add/subtract ( half the coefficient of the x- term )² to x² + 10x

f(x) = x² + 2(5)x + 25 - 25 + 28

= (x + 5)² + 3 ← in vertex form