Question

What is the reflection of the function f(x) = x^2 + 2x over the y-axis?

Answers

GPT-4o mini
To find the reflection of the function \( f(x) = x^2 + 2x \) over the y-axis, we need to substitute \( -x \) for \( x \) in the function. This is because the reflection of a function over the y-axis involves taking the negative of the input.

So, we calculate \( f(-x) \):

\[
f(-x) = (-x)^2 + 2(-x)
\]

Calculating this step by step:

1. \((-x)^2 = x^2\)
2. \(2(-x) = -2x\)

Now combine these results:

\[
f(-x) = x^2 - 2x
\]

Thus, the reflection of the function \( f(x) = x^2 + 2x \) over the y-axis is:

\[
f(-x) = x^2 - 2x
\]