Synopsis

#include <math.h>

double sqrt(double x);

float sqrtf(float x);

long double sqrtl(long double x);

Status

Partially implemented

Conformance

IEEE Std 1003.1-2017

Description

These functions shall compute the square root of their argument x, An application wishing to check for error situations should set errno to zero and call feclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, if errno is non-zero or fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an error has occurred.

Return value

Upon successful completion, these functions shall return the square root of x. For finite values of x < -0, a domain error shall occur, and either a NaN (if supported), or an implementation-defined value shall be returned. If x is NaN, a NaN shall be returned. If x is ±0 or +Inf, x shall be returned. If x is -Inf, a domain error shall occur, and a NaN shall be returned.

Errors

These functions shall fail if:

Domain Error - the finite value of x is < -0,  or x is -Inf. If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, then errno shall be set to EDO. If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, then the invalid floating-point exception shall be raised.

Tests

Untested

Known bugs

None

See Also

  1. Standard library functions
  2. Table of Contents