Manpages - sqrt.3

sqrt, sqrtf, sqrtl - square root function

  #include <math.h>

  double sqrt(double x);
  float sqrtf(float x);
  long double sqrtl(long double x);

Link with -lm.

Feature Test Macro Requirements for glibc (see *feature_test_macros*(7)):

*sqrtf*(), *sqrtl*():

      _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
          || /* Since glibc 2.19: */ _DEFAULT_SOURCE
          || /* Glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

These functions return the nonnegative square root of x.

On success, these functions return the square root of x.

If x is a NaN, a NaN is returned.

If x is +0 (-0), +0 (-0) is returned.

If x is positive infinity, positive infinity is returned.

If x is less than -0, a domain error occurs, and a NaN is returned.

See *math_error*(7) for information on how to determine whether an error has occurred when calling these functions.

The following errors can occur:

Domain error: x less than -0

errno is set to EDOM. An invalid floating-point exception (FE_INVALID) is raised.

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

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

The variant returning double also conforms to SVr4, 4.3BSD, C89.

*cbrt*(3), *csqrt*(3), *hypot*(3)

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