For $0<p-1<q$ and either $ϵ=1$ or $ϵ=-1$, we prove the existence of solutions of $-{\Delta }_{p}u=ϵu^q$ in a cone $C_S$, with vertex 0 and opening $S$, vanishing on $\partial C_S$, of the form $u\left(x\right)={\left|x\right|}^{-\beta }\omega (x/\left|x\right|)$. The problem reduces to a quasilinear elliptic equation on $S$ and the existence proof is based upon degree theory and homotopy methods. We also obtain a nonexistence result in some critical case by making use of an integral type identity.

In this paper, we are concerned with the existence of solutions of the following multi-point boundary value problem consisting of the higher-order differential equation $$x^{\left(n\right)}\left(t\right)=f(t,x\left(t\right),x^{\text{'}}\left(t\right),\cdots ,x^{(n-1)}\left(t\right))+e\left(t\right),0<t<1,(*)$$ and the following multi-point boundary value conditions $$\begin{array}{cc}\hfill 1*-1x^{\left(i\right)}\left(0\right)& =0fori=0,1,\cdots ,n-3,\hfill \\ \hfill x^{(n-1)}\left(0\right)& =\alpha x^{(n-1)}\left(\xi \right),x^{(n-2)}\left(1\right)=\sum _{i=1}^m{\beta }_i{x}^{(n-2)}\left({\eta }_i\right).**\hfill \end{array}$$ Sufficient conditions for the existence of at least one solution of the BVP $(*)$ and $(**)$ at resonance are established. The results obtained generalize and complement those in [13, 14]. This paper is directly motivated by Liu and Yu [J. Pure Appl. Math. 33 (4)(2002), 475–494...