NAME

csqrt, csqrtf, csqrtl — complex square root

SYNOPSIS

Math Library (libm, -lm)
#include <complex.h>

double complex
csqrt(double complex z);

float complex
csqrtf(float complex z);

long double complex
csqrtl(long double complex z);

DESCRIPTION

The csqrt(), csqrtf() and csqrtl() functions compute the complex square root of z.

If z = x + iy, then

Re csqrt(z) = [ (|z| + x) / 2 ]^(1/2).
Im csqrt(z) = [ (|z| - x) / 2 ]^(1/2).

Note that -csqrt(z) is also a square root of z. The root chosen is always in the right half plane and Im csqrt(z) has the same sign as y.

RETURN VALUES

The csqrt(), csqrtf() and csqrtl() functions return the complex square root of z.

SEE ALSO

cpow(3)

STANDARDS

The csqrt(), csqrtf() and csqrtl() functions conform to ISO/IEC 9899:1999 (“ISO C99”).