Which of the following functions have y-axis symmetry?

Alternative  A is the correct answer.

Step-by-step explanation:

For a function to have y-axis symmetry then it must be an even function such that; f(-x) = f(x). In alternative A, y = x^2 is an even function since; y(-x) = (-x)^2 =   x^2 = y(x). The second function is also even since it has the absolute symbol. Finally, the cosine function is always an even function since cos(-x) = cos(x)

d. vertex

step-by-step explanation:

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