User Portlet

p[q_] := q^-\[Delta]; Solve[q + (p[q] - \[Tau])/p'[q] == 0 && 1 > \[Delta] > 0 && \[Tau] > 0 && q > 0, q] The solution I expect is q = ((1 - \[Delta])/\[Tau])^(1/\[Delta]) However, I just get "This system cannot...