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You start with what is given, then progress logically step-by-step -- giving a definition, axiom, or previously proved theorem as a reason, until you reach the desired conclusion.  That's all anyone can tell you given the paucity of information you provided in the question.  Ask something specific, and you might get a specific answer in return.


John
*[tex \LARGE e^{i\pi} + 1 = 0]
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