Triple Angle Formulas/Hyperbolic Cosine

Theorem

 * $\cosh \left({3 x}\right) = 4 \cosh^3 x - 3 \cosh x$

where $\cosh$ denotes hyperbolic cosine.

Also see

 * Triple Angle Formula for Hyperbolic Sine
 * Triple Angle Formula for Hyperbolic Tangent


 * Quadruple Angle Formula for Hyperbolic Sine
 * Quadruple Angle Formula for Hyperbolic Cosine
 * Quadruple Angle Formula for Hyperbolic Tangent