You are Here: Home >< Maths

# trigonemtry using CAST method

Announcements Posted on
Why bother with a post grad? Are they even worth it? Have your say! 26-10-2016
1. hey need help, does anyone know how to solve cos3x = 0.5 using the cast method? I only know how to solve for x from ranges 0 - 360 so only pick up like 2 /4 marks in these type of questions, but does any one how to solve for x above 360 degrees ??????
2. (Original post by trianglelifx)
hey need help, does anyone know how to solve cos3x = 0.5 using the cast method? I only know how to solve for x from ranges 0 - 360 so only pick up like 2 /4 marks in these type of questions, but does any one how to solve for x above 360 degrees ??????
Add 360 and 720 (or 2 pi and 4pi if it's radians) to the two answers you got for cos^-1 (0.5)

Posted from TSR Mobile
3. (Original post by gdunne42)
Add 360 and 720 (or 2 pi and 4pi if it's radians) to the two answers you got for cos^-1 (0.5)

Posted from TSR Mobile
Thanks!

## 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: May 23, 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

### Who is getting a uni offer this half term?

Find out which unis are hot off the mark here

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