d"'= 1/u - x/u^2 * du/dx d""= 1/u^2 -1/u^2 du/dx +2x/u^3 (du/dx)^2- x/u^2 d"u/dx" so now it is the algebra du/dx= 2x d"u/dx"= 2 go for it. check my work.
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