Common things to watch out for when doing trigonometric proofs:

• Try to start with the left hand side, and arrive at the right hand side.


• If it is taking a while and you are not arriving at the right hand side, you could try to manipulate the right hand side and "meet in the middle".


• However, you should "reverse engineer" your working out and still present your method as having started from the left hand side and arriving at the right hand side.


• There are often more than one way of starting a question, and not all of them will arrive at the answer.


• If, after a few steps, you can't see how you will ever arrive at the right hand side, start again and try to use a different identity.


• Generally, if there are separate fractions, try to combine them using a common denominator.


• Every proof question is different, but if you practise enough questions, it is unlikely that a completely unexpected question will come up.