Question

How do you evaluate `Arcsin (sin ((10pi)/(11)))`?

Answer 1

`arcsin(sin((10pi)/11)) = pi/11`

Explanation:

If `theta` is within the range `[-pi/2,+pi/2]`
then `arcsin(sin(theta)) = theta`

`(10pi)/11` is not within this range but

`sin((10pi)/11) = sin(pi/11)`
and
`(pi/11)` is within the required range.