Question

Find the line of symmetry for the parabola whose equation is y = 2 x2 - 4 x + 1.

a. x=-1
b. x=1
c. x=2

Answer 1

Move all terms to one side:
y - 2x^2 + 4x -1 = 0
Use the Quadratic Formula:
x = -4 + 2√2(y + 1)/-4, -4 - 2√2(y + 1)/-4
Simplify solutions:
x = 1 - √2(y + 1)/2, 1 + √2(y + 1)/2