You are Here: Home >< Maths

# Trig functions powers

Announcements Posted on
TSR's new app is coming! Sign up here to try it first >> 17-10-2016
1. I was wondering why sin^2(x) = (sin(x))^2 ​​but sin^-1(x) ≠ (sin(x))^-1 ?
2. It's really just because of unfortunate notation.

sin-1(x) the way you know it means "the inverse of sine" meaning that if sin(a) = b then sin-1(b) = a.

unfortunately this clashes with when we say sin^2(x) meaning sin(x)^2

To avoid this you can use arcsin, arccos and arctan (short for arcsine, arccosine and arctangent) meaning "the inverse of sine..." etc

To write 1/sinx I would either write just that (1/sinx) or sin(x)^-1 to avoid confusion.

## Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank
2. this can't be left blank
3. this can't be left blank

6 characters or longer with both numbers and letters is safer

4. this can't be left empty
1. Oops, you need to agree to our Ts&Cs to register

Updated: October 7, 2016
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:
Today on TSR

### How does exam reform affect you?

From GCSE to A level, it's all changing

Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read here first

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams