Question

Which of the following is an even function?

g(x) = (x – 1)2 + 1
g(x) = 2x2 + 1
g(x) = 4x + 2
g(x) = 2x

Answer 1

B. g(x) = 2x2 + 1

Correct on edge

Answer 2

• B. g(x) = 2x² + 1

Explanation:

Even function has following property:

• g(x) = g(-x)

It is easy to show this works with the second choice only. All the others don't work:

• g(x) = (x - 1)² + 1
• g(-x) = (-x - 1)² + 1

This is not correct as x - 1 ≠ -x - 1 so as their squares, so g(x) ≠ g(-x)

The last two choices are not even similarly.