Acos (Tag-based PE function)

Return the inverse cosine (arccos) of an integer or real number. The inverse cosine of x is the angle in radians whose cosine is equal to x.

Syntax

Acos(x)

Arguments

x

Must be a real number between -1.0 and 1.0, inclusive.

Returns

The inverse cosine of x, in radians.

Exceptions

If x is not a number, or is less than -1.0 or greater than 1.0, returns an error value.

Example

Acos(-0.5) [Returns 2.0944]

Acos(0.75) [Returns 0.72273]