solve (a>, , < , using ODE d'A (a) (c) (4) dx d'A dx d'A dx1 du dx + + + dA dx JA dx JA dx + e* =0 + 4 = 0 + sin(x)=0 + Usin(x) = sin(x) 1 " " " A = 1 A=1 A =1 A = 1 at at at at x = 0,1 X1=2,1 X=D, I x=0 " / use ex = (as(x) + sin(x) we integrating factor