mathjs/docs/reference/functions/acos.md

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Function acos #

Calculate the inverse cosine of a value.

To avoid confusion with the matrix arccosine, this function does not apply to matrices.

Syntax #

math.acos(x)

Parameters #

Parameter	Type	Description
x	number | BigNumber | Complex	Function input

Returns #

Type	Description
number | BigNumber | Complex	The arc cosine of x

Throws #

Type	Description

Examples #

math.acos(0.5)           // returns number 1.0471975511965979
math.acos(math.cos(1.5)) // returns number 1.5

math.acos(2)             // returns Complex 0 + 1.3169578969248166 i

See also #

cos, atan, asin