Question 451956
My advice is that when you are asked to prove something, make sure you prove exactly what it says and that all exceptions are covered for. Do not merely make assumptions (e.g. if you are asked to prove the area of a triangle A = bh/2, do not assume that one side is the base and another is the height, implying a 90 degree angle) unless you can show that all other cases are analogous.


When writing a formal proof, always make sure you are as concise as possible. Most proofs are expressed as a two-column proof or as a paragraph proof, or "essay" (I prefer the paragraph proof since it can be applied to various types of proof).


The Wikipedia article for "mathematical proof" details some common proof techniques: http://en.wikipedia.org/wiki/Mathematical_proof