Question

8. What transformation is made from f(x) → f(-x)?

O reflection across the x-axis
O reflection across the y-axis
Osliding it down
O rotation around the origin

Answer 1

Answer: Choice B. reflection across the y-axis

Reason: Each input x is the opposite as -x.

For instance, x = 2 flips to x = -2

Another example: x = -7 flips to x = 7

Because x flips like this, we have a reflection over the vertical y axis.

The parabola f(x) = x^2 is one example function that makes f(x) = f(-x) true. Notice the symmetry along x = 0.