Microsoft® Excel® 2010 Formulas & Functions Inside Out

ACOSH()

Syntax. ACOSH(number)

Definition. This function returns the inverse hyperbolic cosine of a number (see Figure 16-3). The definition range spans x = +1 to + ∞.

Argument

• number (required) A real number equal to or greater than 1.

Background. The inverse hyperbolic functions are also called the area hyperbolic functions. They are the inverse functions of the hyperbolic functions. The hyperbolic functions sinh, tanh, and coth are strictly monotonic and have one inverse function. The cosh function, however, has two monotonic intervals symmetrical to the positive segment of the ordinate and two inverse functions:

y = arcosh x

and

y = -arcosh x

where:

The graph (see Figure 16-3) starts at point 1.0 and is monotone increasing or decreasing.

Note

Inverse ...