Returns the inverse hyperbolic cosine of the given number in radians.

**Sample Usage**

ACOSH(0.5)

ACOSH(C5)

**Syntax**

ACOSH(number)

- number - The number for which the inverse hyperbolic cosine is to be computed.

**Examples**

ACOSH(5) returns the inverse hyperbolic cosine of 5 in radians.

ACOSH(C5) returns the inverse hyperbolic cosine of the number contained in C5.

**Notes**

- The number passed as an argument must be greater than or equal to
`1`

.