1. 1/a^8 (Sorry I can't find out what the others are)
Answer:
BCE
Step-by-step explanation:
I hoped this helped and mark me as brainly pls
Answer: 
Step-by-step explanation:
Given

We can write it as

Express x in terms of y

Replace y be x to get the inverse

To prove, it is inverse of f(x). 

So, they are inverse of each other.
we can factor the whole thing:
(2sin(x) -1)(sin(x)+1) = 0.
Therefore, sin(x) = -1 and sin(x) = 1/2.
For the first one x = 3π/2 and the second is π/6 and 5π/6
So 3π/2, π/6 and 5π/6 are the solutions.
I do kind of have a problem with this because it doesn't mention if you should go over 360°. Otherwise, you have to add in an 2nπ into the equations like 3π/2 + 2nπ; 
but I don't know if that is necessary for you.
Regroup terms
Add 2x to both sides
Simplify 4 - x + 2x to 4 + x
subtract 4 from both sides
subtract -6 - 4.
Answer: x = -10