Question

Find the vertex of this parabola. y = -2x2 + 4x + 12 A. (-4, 12) B. (-2, 6) C. (3, 6) D. (1, 14)

Answer 1

Answer: the answer is d

Answer 2

D

given the equation of a parabola in standard form : ax² + bx + c = 0 ( a ≠ 0 )

then the x-coordinate of the vertex = -
`(b)/(2a)`

y = - 2x² + 4x + 12 is in standard form

with a = - 2, b= 4 and c = 12

`x_(vertex)` = -
`(4)/(-4)` = 1

substitute x = 1 into the equation for y

y = - 2(1)² + 4(1) + 12 = 14

vertex = (1, 14 )