1. The problem statement, all variables and given/known data Find an integer c such that the equation 4x^3 + cx - 27 = 0 has a double root. 2. Relevant equations Ax^3+Bx^2+Cx+K = 0 Sum of Roots = -B/A Product of Roots = (-1)^n * k/a etc. 3. The attempt at a solution I tried using P/Q with synthetic division to find a quadratic for the problem but I couldn't find a way to get rid of or solve for C. I also tried manipulating the Sum of Roots and Product of Roots (both listed above) relationships to try and solve for C. No success here. I have a hunch that it has to deal with the Sum of Roots & Product of Roots relationships, since I know what A is (leading coefficient) and I know what K is (-27, given). I just can't seem to put it together. The answer of the problem is C = -27, however I would like to know how to get this. Thank you very much.