Acos()

acos(<number>[, <units>])

Returns the arc-cosine of <number>. The value returned will be expressed in <units>.

<units> may be 'radians', 'degrees', or 'gradians' or just the first letter of any of these. By default, <units> is 'radians'.

In a circle, there are 2*pi() radians, 360 degrees, and 400 gradians.

Example

> say acos(0)

You say, "1.570796"

> say acos(1)

You say, "0"

> say acos(0.707101)

You say, "0.785406"

> say acos(0.866025)

You say, "0.5236"

Related Topics

asin(), atan(), cos(), pi(), sin(), tan()