True or false: When subject to homogeneous Dirichlet boundary conditions on an in- terval [a,b], every nonsingular second-order linear ordinary differential equation a(x)u" + 6(x) u' + c(u) u = f(x) is (a) self-adjoint, (b) positive definite, (c) positive semi- (x ( definite, with respect to some weighted inner product (9.76).