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atan

(PHP 3, PHP 4, PHP 5)

atan -- Arc tangent

Description

float atan ( float arg )

Returns the arc tangent of arg in radians. atan() is the complementary function of tan(), which means that a==tan(atan(a)) for every value of a that is within atan()'s range.

Parameters

arg

The argument to process

Return Values

The arc tangent of arg in radians.

See Also

tan()
atanh()
asin()
acos()

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