It is proved that the elliptic problem on a bounded domain with smooth boundary has two sign-changing solutions and one positive solution if satisfies for some i[greater-or-equal, slanted]2, , and , where [mu]1<[mu]2[less-than-or-equals, slant][mu]3[less-than-or-equals, slant]... are eigenvalues of -[Delta] with 0-Dirichlet boundary condition on [Omega] counting with their multiplicity.
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