x Turn on thread page Beta
 You are Here: Home >< Maths

# Arcsin x watch

1. Can we think of angle y in quadrant II? As its in interval [0, pi]
2. (Original post by mystreet091234)
Can we think of angle y in quadrant II? As its in interval [0, pi]
Yes.
3. (Original post by HapaxOromenon)
Yes.

But how?
4. (Original post by mystreet091234)

But how?
Actually scrap that and just do this:
Let arccos x = y.
Then x = cos y = sin(π/2 - y) (you can verify this by the subtraction formula for cos)
and so arcsin x = π/2 - y by taking arcsin of both sides.

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: March 28, 2016
Today on TSR

### Loughborough better than Cambridge

Loughborough at number one

Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams