Question

Which of the following functions have y-axis symmetry?

Answer 1

Alternative A is the correct answer.

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)

Answer 2

Option: A is the correct answer.

y=x^2, y=|x| , y=cos (x)

Explanation:

We are asked to find which of the following functions have y-axis symmetry means that which graph on rotating about the y-axis retains it's original shape i.e. the image and pre-image are the same on rotating the pre-image about the y-axis.

We know that the graph of y=x^2

y=|x|

and y=cos (x) are symmetric about the the y-axis.

Hence, option: A is the answer.