Common things to watch out for when doing trigonometric proofs: ulliTry to start with the left hand side, and arrive at the right hand side./liliIf 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"./liliHowever, 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./liliThere are often more than one way of starting a question, and not all of them will arrive at the answer./liliIf, 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./liliGenerally, if there are separate fractions, try to combine them using a common denominator./liliEvery proof question is different, but if you practise enough questions, it is unlikely that a completely unexpected question will come up.[/li]/ul