ATAN function

Returns the arctangent, or inverse tangent, of a number. The arctangent is the angle whose tangent is number. The returned angle is given in radians in the range -pi/2 to pi/2.

Syntax

ATAN(number)

Number     is the tangent of the angle you want.

Remark

To express the arctangent in degrees, multiply the result by 180/PI() or use the DEGREES function.

Examples

Formula	Description (Result)
=ATAN(1)	Arctangent of 1 in radians, pi/4 (0.785398)
=ATAN(1)*180/PI()	Arctangent of 1 in degrees (45)
=DEGREES(ATAN(1))	Arctangent of 1 in degrees (45)