Existence of Solution for a Boundary Value Problem of Fractional Order

The existence of one solution for a boundary value problem of fractional order is considered,involving α∈(3,4],Dα0+u(t)+f(t,u(t),u′(t))=0u(0)=0,u′(0)=0u″(1)=0,u'''(1)=g(u(1)) by using the Schauder fixed point theorem.