Updated: 2022/Sep/29
Please read Privacy Policy. It's for your privacy.
ACOS(3) Library Functions Manual ACOS(3) NAME acos, acosf, acosl - arc cosine function LIBRARY Math Library (libm, -lm) SYNOPSIS #include <math.h> double acos(double x); float acosf(float x); long double acosl(long double x); DESCRIPTION The acos(), acosf(), and acosl() functions compute the principal value of the arc cosine of x in the range [0, pi]. RETURN VALUES If |x|>1, acos(x), acosf(x), and acosl(x) set the global variable errno to EDOM. SEE ALSO asin(3), atan(3), atan2(3), cos(3), cosh(3), math(3), sin(3), sinh(3), tan(3), tanh(3) STANDARDS The acos() function conforms to ISO/IEC 9899:1999 ("ISO C99"). NetBSD 10.99 January 29, 2013 NetBSD 10.99