Here are some important identities regarding the hyperbolic trigonometric functions. It's useful to contrast these identities with the familiar circle trigonometric functions. Hyperbolic Trig Circle Trig dt d sinh(t) = d dt sin (t) - d d dt cosh (t) = cos (t) - cosh2 (t) - sinh2 (t) = Number cos - (t) + sing (2) - Number Note: the Maple syntax for cosh(t) is cosh (t)