The Inverse Hyperbolic Cosine Function: acosh

Syntax
y = acosh(x)

Description
The inverse hyperbolic cosine function is defined by x == cosh(y) .

x, y
See the possible types for a unary standard math function.

If this preprocessor symbol is true (1), and x is an AD type, this is an atomic operation .
If this preprocessor symbol is false (0), CppAD uses the representation $$\R{acosh} (x) = \log \left( x + \sqrt{ x^2 - 1 } \right)$$ to compute this function.