Question

What are the coordinates of the vertex of the graph of the function y = –3x² –12x + 3? A. (–2, 29) B. (2, –15) C. (2, –9) D. (–2, 15)

Answer 1

D (-2,15)

Explanation:

To find the vertex from the standard form of the equation, use the formula x = -b/2a. Then substitute the x value into the equation to find the y value.

Here a = -3 and b = -12.

So x = -(-12) / 2(-3) = 12 / -6 = -2.

Substitute x = -2 and solve for y.

y = -3(-2)^2 - 12(-2) + 3

y = -3(4) + 24 + 3

y = -12 + 24 + 3

y = 12 + 3

y = 15