Calculates the hyperbolic cosine of a value. The hyperbolic trig functions sinh(, cosh(, and tanh( are an analog of normal trig functions, but for a hyperbola, rather than a circle. They can be expressed in terms of real powers of e, and don't depend on the Degree or Radian mode setting.
cosh(0) 1 cosh(1) 1.543080635
Like normal trig commands, cosh( works on lists as well, but not on complex numbers, even though the function is often extended to the complex numbers in mathematics.
The definition of hyperbolic cosine is:(1)