NAME atan, atanf - arc tangent functions of one variable CONTENTS Library Synopsis Description Return Values See Also Standards LIBRARY .Lb libm SYNOPSIS .In math.h double atan "double x" float atanf "float x" DESCRIPTION The atan and the atanf functions compute the principal value of the arc tangent of x. For a discussion of error due to roundoff, see math(3). RETURN VALUES The atan and the atanf function returns the arc tangent in the range .Bk -words [-pi/2, +pi/2] .Ek radians. SEE ALSO acos(3), asin(3), atan2(3), cos(3), cosh(3), math(3), sin(3), sinh(3), tan(3), tanh(3) STANDARDS
