sqrt() function not working with variable arguments [duplicate]

Answer 1

Compile with:

gcc -Wall -o test2 test2.c -lm

You need to link against the math library.

Answer 2

This works fine for me. I think there is some problem with ur math library. Try linking it again and see. Other wise code is completely perfect.

Answer 3

In case of gcc you need to link the library.

gcc filename.c -lm .

However in case of g++ no need to link the library so this will work fine :

g++ filename.c -o filename Once compilation is successful.

To run simply enter ./filename in G++. and enter ./a.out in Gcc.

Answer 4

You need to link with the math library (use a '-lm' on the command line). In the constant case, the compiler is probably being smart and precomputing sqrt(2.0) (so the code that is compiled is essentially 'b = 1.414...;')

Answer 5

gcc does not link the standard libraries by default. So you just need to do this if compiling via gcc:

gcc filename.c -lm .

However in case of g++ no need to link the library so this will work fine :

g++ filename.c -o filename

Answer 6

You probably need to add -lm when you compile. When you take the square root of a constant, the compiler is optimizing the code by taking the square root while it compiles, so it doesn't use sqrt at all.