If two function images are symmetric about the Y axis, then what is their relationship

If two function images are symmetric about the Y axis, then what is their relationship

If f (x) and G (x) images are symmetric about y axis, then f (x) = g (- x)

Which of the following functions is symmetric about the Y axis
①y=-2x^2
②y=-2x+1
③y=x
④y=x^2

A:
A function with Y-axis symmetry and domain symmetry must be even
A) Y = - 2x & # 178; is even function
B) Y = - 2x + 1 non odd function non even function
C) Y = x is an odd function
D) Y = x & # 178; is even function
So: there are (1) and (4) functions about Y-axis symmetry

The image of the function y = x times 1 / 2 - 1 is approximately x-symmetric

For X-axis symmetry, then y = - Y
That is y = - x times 1 / 2 + 1