double
sqrt(double x);
long double
sqrtl(long double x);
float
sqrtf(float x);
The sqrt() function compute the non-negative square root of x.
sqrt(-0) returns -0.
sqrt(x) returns a NaN and generates a domain error for x < 0.
math(3)
The sqrt() function conforms to ISO/IEC 9899:1999(E).
BSD January 27, 2003 BSD