(L+)2+2 ∈rI (L+u)2+(L-)2 L U==AEL L)+AEV2I 2("乙)} Note that we have written U=U(u, v). According to the theorem 0 aU See solution in accompanying mathematica file. 5� � (L + u)2 + v2 u �I = − 1 ∼ L2 L (L + u)2 + (L − v)2 1 u − v �I I = − 1 ∼ 2L2 2 L 1� � u �2 √ �1�u − v��2� U = AEL + AE 2L 2 L 2 L Note that we have written U = U(u, v). According to the theorem: ∂U 0 = ∂u ∂U F = ∂v See solution in accompanying mathematica file. 5