Two polynomials P(x)=x4+ax3+bx2+cx+d and Q(x)=x2+px+q have real coefficients, and I is an interval on the real line of length greater than 2. Suppose P(x) and Q(x) take negative values on I, and they take non-negative values outside I. Prove that there exists a real number x0 such that P(x0)<Q(x0). algebrapolynomialquadraticsalgebra unsolved