The Trigonometric Double Angle identities or Trig Double identities actually deals with the double angle of the trigonometric functions. For instance,

**Sin2(α)****Cos2(α)****Tan2(α)****Cosine2(α)****Sec2(α)****Cot2(α)**

Double Angle identities are a special case of **trig identities** where the double angle is obtained by adding 2 different angles. In this article, we will cover up the different aspects of Trig Double Identities. Before Double, You must have an understanding of **Trig Basic Identities**.

**Trig Double Identities – Trigonometric Double Angle Identities **

Here are some of the formulas which are expressing the trigonometric double angled identities in terms of angle x.

Sin(2x) | = | 2sinxcosx |

Cos(2x) | = | Cosˆ2x – Sinˆ2x |

= | 2cosˆ2x -1 | |

= | 1- 2sinˆx 1 | |

Tan(2x) | = | 2tanx/1-tanˆ2x |

If you are looking for Trig Hyperbolic Identities for Trig Double Angle identities then here comes. You can also learn about **Hyperbolic Trig Identities**.

Sinh (2x) | = | 2 sinh x cosh x |

Cosh (2x) | = | 2coshˆ2 -1 |

Tanh (2x) | = | 2 tanh x/1+tanhˆ2x |