1. The problem statement, all variables and given/known data Find a value of k such that the limit exists lim (x2-kx+4)/(x-1) x->1 3. The attempt at a solution In the solution they set the top equal to zero finding that k is equal to 5. Why do you assume the numerator must equal zero if the denominator equals zero? Is this the only case in which the limit exists? If so why?