How to expand the power function of Ln (1-x) / (1 + x)

How to expand the power function of Ln (1-x) / (1 + x)

So m ^ 2-2m-3 is even
In the interval (0, + ∞) is a decreasing function, so m ^ 2-2m-3 < 0
The solution is m ^ 2-2m-3 = - 4
f(x)=x^-4

Is y = x a power function

Yes, a ∈ r in the power function y = x ^ a

Are y = x ^ 2 + X and y = 1 power functions?
Is that why

Neither of them
The definition of power function is y = x ^ a (a is a real number not equal to 0)

Is y = 1 / x power function

It's a power function
This function can be reduced to y = x ^ (- 1)
Power function y = x ^ α (x ≠ 0)
These are what I learned