I'm trying to write a program for class and I can't get my fractional exponent to work. I've tried using 2/3 2.0/3.0 and I've tried entering 2/3 into a separate variable, but nothing seems to work. I don't get any errors while building 2/3 but the logic does not come out correctly. I keep getting "undefined reference to 'pow' as an error which doesn't seem right at all because I'm entering two parameters as required. Here is my code:
//find hydraulicRadius to the power of 2/3
double twobythree = 2.0/3.0;
printf("%lf = 2/3\n", twobythree);
double r = pow (hydraulicRadius, twobythree);