Find all rational zeros of the polynomial, and then find the irrational zeros, if any. Whenever appropriate, use the Rational Zeros Theorem, the Upper and Lower Bounds Theorem, Descartes' Rule of Signs, the Quadratic Formula, or other factoring techniques. (Enter your answers as comma-separated lists. Enter all answers including repetitions. If an answer does not exist, enter DNE.) P(X) = 4x4 - 21x2+ 5 rational zeros X : irrational zeros X = Need Help? Read It Watch It