We consider the eigenvalue problem for t ? 0, b], where an = |a|n sgna, a ? ?, λ ? ?, the constants μ, v are real such that 0 ≤ μ < n and derive asymptotic estimates for solutions of the differential equation in the definite case q(t)> 0 which corresponds to the well-known WKB-approximation in the linear case n = 1, μ = 0. In the second part we investigate the asymptotic distribution of the eigenvalues in the general case of two -point boundary conditions and refine these results for the so called separated boundary conditions.
