atan

(PHP 4, PHP 5, PHP 7)

atan — Arc tangent

Description

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() - Tangent

• atanh() - Inverse hyperbolic tangent

• asin() - Arc sine

• acos() - Arc cosine

← atan2

atanh →

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https://secure.php.net/manual/en/function.atan.php