Math Problem Solver

explain in detail, Determine the Lagrange multiplier $\lambda(\xi)$ by the variational condition $\delta u_{m+1}=0$. Two integrations by parts give

$$\lambda''(\xi)=0,\qquad \lambda(x)=0,\qquad \lambda'(x)=-1,$$

so that

$$\boxed{\;\lambda(\xi)=\xi-x\;}. $$