Therefore, the symmetric resolution function of y2 about the y axis is y=cos[2(-x)-π/3]=cos(2x+π/3).

2) Substitute x=π/8 into the resolution function to get SIN (π/4+A) = 1,

So π/4+a=π/2+kπ, k ∈ z.

So a=π/4+kπ, k ∈ z.

Because-π

You ask the second question, and the answer is 2π/8+A = 2π+π/2, and then you calculate a =-3π/4. What does this mean?

First, this analysis is wrong.

2.y=f(x) The symmetry axis of an image is a straight line x=π/8, so when x=π/8, f(x) must take the maximum or minimum value, that is, 1 or-1.

So π/4+a=π/2+kπ (here, the terminal edge may be on the positive or negative half axis of the Y axis.

This gives a =-3π/4.

but

The analysis is 2 π/8+a=2kπ+π/2. Only the positive semi-axis of the end edge on the Y axis is taken, and then-π is merged.

In another case, a =-3π/4 is obtained.