Trigonometric identities

Revision as of 23:53, 23 June 2006 by Mysmartmouth (talk | contribs)

Trigonometric identities are used to manipulate trig equations in certain ways. Here is a list of them:


Reciprocal Identities

Pythagorean Identities

  • $\displaystyle \sin^2x + \cos^2x = 1$
  • $\displaystyle 1 + \cot^2x = \csc^2x$
  • $\displaystyle \tan^2x + 1 = \sec^2x$

Double Angle Identities

Even-Odd Identities

Other Identities

  • $|1-e^{i\theta}|=2\sin\frac{\theta}{2}$

This page is incomplete--if you know of a trigonometric identity, add it.

See also

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