Don't know about an infinite loop, but I think you'll find that
doesn't do what you think it does ... and I couldn't see any reason for using it if it did. Also, division by 1.0 is a bit of a pointless operation: have you mistaken this for something else?
Please put your code in code tags, use consistent indentation, make sure that it has an int main() driving function, and change the magic number 3.14159 to a named constant PI.
It appears to be a double integral; perhaps you would like to point us to precisely what the integrand ought to be.