Answer:
D
Explanation:
The equation of a parabola in vertex form is
f(x) = a(x - h)² + k
where (h, k) are the coordinates of the vertex and a is a multiplier
To obtain this form using the method of completing the square.
Given
f(x) = 3x² - 24x + 10
We require the coefficient of the x² term to be 1 , thus factor out 3
3(x² - 8x) + 10
To complete the square
add/subtract ( half the coefficient of the x- term )² to x² - 8x
= 3(x² + 2(- 4)x + 16 - 16) + 10
= 3(x - 4)² + (3 × - 16) + 10
= 3(x - 4)² - 48 + 10
= 3(x - 4)² - 38, thus
f(x) = 3(x - 4)² - 38 ← in vertex form