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Proving Trigonometric Identities

The best way to learn how to prove trigonometric identities is to do lots of example, there being ever so many identities to prove.

Example: Prove

Now divide every term in the numerator and denominator byto give

Example: Prove the identity

Divide every term in the numerator and denominator byto give

Now perform long division in the to get

Example:

Example: Prove