Answer:

Step-by-step explanation:
I am going to assume that by "f-1(x)" you mean
, which makes this an inverse function problem. To find the inverse of a function, simply swap x and y, then solve for y.

Answer:
Step 1:
✔ Cofunction identity
Step 5:
✔ Sine difference identity
Step 6:
✔ Cofunction Identity
Step 7:
✔ Cosine function is even, sine function is odd.
Step-by-step explanation:
The answer to that question is 4