Choose the equation below whose axis of symmetry is x = 2.
y = x² + 4x + 2
y = x² - 4
y = x² - 2
y = x² - 4x + 2 

Solution:

Given axis of symmetry x = 2

The axis of symmetry is the vertical line that goes through the vertex of a parabola so the left side and the right side of it are symmetrical.

The axis of symmetry for ax² + bx + c is given as x = -b/2a

Equate x = 2 with x = -b/2a

⇒ -b/2a = 2

Now, check the options, which satisfy this condition.

We get x² - 4x + 2 as the required equation [since -(-4)/2 = 2]

Choose the equation below whose axis of symmetry is x = 2.

Summary:

The equation is x² - 4x + 2 whose axis of symmetry is x = 2.