what is 'undefined reference to `pow''
c
Solution
You need to link with the math library. With gcc, this would mean passing `-lm` during linking.
The reason it doesn't complain when you use `2` as the exponent value is because the compiler is optimizing the `pow` call out.
Problem
I have a codepad . On line 15 inside a for function ``` for(i=2; i<=90; i+=2){ int j=0+i; printf("%i\n",i); power=pow(inp,j); factor=factorial(i); if(i%4==0)fAns += power/factor; else fAns -= power/factor; } ``` the line `power=pow(inp,j);` I added `j` instead of just using `i` because it gave me the same error. `undefined reference to 'pow'`. If I replace `j` with 2, then it works just fine but when I use `j=i` it wont work. Is there a problem with incrementing this line? I want this to increment and not throw me an error.