Question

The first steps in writing f(x) = 3x2 – 24x + 10 in vertex form are shown.f(x) = 3(x2 – 8x) + 10 (-8/2)^2 = 16 What is the function written in vertex form? A.f(x) = 3(x + 4)2 – 6 B.f(x) = 3(x + 4)2 – 38 C.f(x) = 3(x – 4)2 – 6 D.f(x) = 3(x – 4)2 – 38

Answer 1

Answer:

D

Step-by-step explanation:

Given

f(x) = 3x² - 24x + 10 ← factor out 3 from 3x² - 24x

     = 3(x² - 8x) + 10

Using the method of completing the square

add/ subtract ( half the coefficient of the x- term )² to x² - 8x

f(x) = 3(x² + 2(- 4)x + 16 - 16) + 10

      = 3(x - 4)² - 48 + 10

      = 3(x - 4)² - 38 ← in vertex form → D