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Differential EquationsChallengeExact Equations & Substitutions

Exact Equations & Substitutions · Challenge problem

Use the substitution u=eyu = e^y to solve y′=xe−y−1xy' = xe^{-y} - \dfrac1x for x>0x > 0 with y(1)=ln⁡2y(1) = \ln 2. Find the minimum value of y(x)y(x) on x>0x > 0.