csqrt(3) Library Functions Manual csqrt(3)

csqrt, csqrtf, csqrtl - complex square root

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);

These functions calculate the complex square root of z, 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.)

These functions were added in glibc 2.1.

For an explanation of the terms used in this section, see attributes(7).

Interface Attribute Value
csqrt (), csqrtf (), csqrtl () Thread safety MT-Safe

C99, POSIX.1-2001, POSIX.1-2008.

cabs(3), cexp(3), complex(7)

2022-12-15 Linux man-pages 6.02