Thread: how to use math functions in g++

#include <math>
gives error on linux compiler g++
can anybody guide how functions like sqrt() are to be used

try #include <cmath>

c libraries start with an extra c in c++(ie cmath, cstdio, ctime)

The correct header from C is <math.h>. This is deprecated in C++ so <cmath> should be used instead (in which case math functions like sqrt() will live in namespace std).

The other usual requirement (assuming you have #include'd required headers) is to add -lm to the command line when linking, so as to link functions from the math library into the executable.