You are Here: Home >< Maths

# A2 Maths Trig watch

1. Well basically i can't be asked to do think, if someone will be kind enough to help me with these solutions.

Solve

a) sin2θ=sinθ {0<θ<2pie}

b) cos2θ=1-cosθ {-180*<θ<180*}

c) 2tan2ytany=3 {<y<360*}

Thanks
2. Think graphically or substitute using identities for something squared then solve the quadratic.
3. too tired to think

For a), use the double-angle formula on sin2θ and factorise.
For b), use the double-angle formula on cos2θ and then make it into a quadratic in cosθ.
For c), again, use the double angle formula for tan2y.
6. Think of your double angle formulae.
7. Learn the double angle formulas then have another go

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: November 10, 2008
Today on TSR

### Medicine offers

Find out which unis send them quickest

### University open days

• Sheffield Hallam University
Wed, 17 Oct '18
• Staffordshire University
Wed, 17 Oct '18
• Teesside University
Wed, 17 Oct '18
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