Acos

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]