Which of the following is an even function? a. g(x) = (x – 1)2 + 1 b. g(x) = 2x2 + 1 c. g(x) = 4x + 2 d. g(x) = 2x

The definition of an even function is g(-x)=g(x). In other words, x values of the same magnitude but different signs will produce the same y value. An easy way to recognize this is that the degree of the function is even(for polynomials) and the function is centered at x=0. A is not centered at 0, it is centered at 1. B is an even function because it has an even degree, and is centered at 0. C and D are not even functions because they have odd degrees. So B is the right answer.