When dealing with improper integrals, why would 1/c equal infinity?

For example, integrate the function 1/x^2, with limits of integration at -1 and 2. I break the integral into two parts at the critical value of zero, and replace with constant "c". Now I have -1/x with limit from -1 to c and -1/x with limit from c to 2. The answer key says the second limit, -1/x with limits from c to 2, equals infinity. Why wouldn't it equal -1/2 + 1/c? HELP!