Question

Which statement best describes how to determine whether f(x) = x3 + 5x + 1 is an even function?

Determine whether –(x3 + 5x + 1) is equivalent to x3 + 5x + 1.
Determine whether (–x)3 + 5(–x) + 1 is equivalent to x3 + 5x + 1.
Determine whether –x3 + 5x + 1 is equivalent to –(x3 + 5x + 1).
Determine whether (–x)3 + 5(–x) + 1 is equivalent to –(x3 + 5x + 1).

Answer 1

Answer: Determine whether (–x)3 + 5(–x) + 1 is equivalent to x3 + 5x + 1.

To determine if a function is even, we need to check if f(-x)=f(x).