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<acoshasinh>
^Math FunctionsLast updated: Mon, 26 Oct 2026

asin

(PHP 4, PHP 5, PHP 7, PHP 8)

asin — Arc sine

Description

function asin(float $num): float

Returns the arc sine of num in radians. asin() is the inverse function of sin(), which means that $num == sin(asin($num)) for every value of num that is in the domain of asin().

Parameters

num

The argument to process

Return Values

The arc sine of num in radians

See Also


<acoshasinh>
^Math FunctionsLast updated: Mon, 26 Oct 2026