Question

What is the equation of the line of symmetry for the graph of y = 3(x + 2)2 - 4?

Answer 1

Write the equation in vertex form.

y = 3x² + 12x - 2
= 3(x² + 4x) - 2
= 3(x² + 4x + (4/2)² - (4/2)²) - 2
= 3(x² + 4x + 4) - 3*4 - 2
= 3(x + 2)² - 14

Answer 2

Answer= -14

Answer 3

a. x = -4
b. x = -2
c. x = 2
d. x = 3

Answer 4

Hint : line of symmetry goes thru vertex

Answer 5

y = 3x² + 12x - 2
= 3(x² + 4x) - 2
= 3(x² + 4x + (4/2)² - (4/2)²) - 2
= 3(x² + 4x + 4) - 3*4 - 2
= 3(x + 2)² - 14

The equation for the axis of symmetry is (x + 2) = 0, that is, x = -2. The axis passes through the vertex of the parabola; its coordinates are (-2, -14)