dsolve(diff(diff(y(x),x),x) = (2*JacobiSN(x,k)*JacobiCN(x,k)*JacobiDN(x,k)*diff(y(x),x)-2*(1-2*(k^2+1)*JacobiSN(a,k)^2+3*k^2*JacobiSN(a,k)^4)*y(x))/(JacobiSN(x,k)^2-JacobiSN(a,k)),y(x))