Question

What is the equation of the axis of symmetry of the graph of y + 3x – 6 = –3(x – 2)2 + 4?
A: x=3/2
B: x=-1/6
C: x=-1/2
D: x=-3/2

Answer 1

Axis of symmetry = -b/2a
y + 3x - 6 = -3(x-2)² + 4
y + 3x - 6 = -3 ( x²-4x+4) + 4
y + 3x - 6 = -3x² + 12x -12 + 4
y + 3x - 6 = -3x² + 12x -8
y = -3x² + 12x - 3x -8 + 6
y = -3x² + 9x -2
(a=-3, b=9, c=-2)
Axis of symmetry = -b/2a =  -9/2(-3) = -9 / -6 = -3 / -2 = 3/2
Hence, option A) x=3/2 is the correct answer.