csqrt, csqrtf, csqrtl − complex square root

#include <complex.h>

double complex csqrt(double complex z);

float complex csqrtf(float complex z);

long double complex csqrtl(long double complex z);

Calculate the square root of a given complex number, with nonnegative real part, and with a branch cut along the negative real axis. (That means that csqrt(-1+eps*I) will be close to I while csqrt(-1-eps*I) will be close to -I, if eps is a small positive real number.)

C99

cabs(3), cexp(3)