Find the value of the following:
(Forcos-1(cosx) type of problem we have to always check whether the angle is in the principal range or not. This angle must be in the principal range
.)
So here, 
Now, 
can be written as,
where 
Hence, 
2
Find the value of the following:
(Forcos-1(cosx) type of problem we have to always check whether the angle is in the principal range or not. This angle must be in the principal range.)
So here,
Now, can be written as,
where
Hence,