Forum de Mathématiques: Maths-Forum

Bonjour; \begin{array}{l} y = x\ln 3x \\ y^, = \ln (3x) + 1 \\ y^, (x_1 ) = \ln (3x_1 ) + 1 \\ y^, (\frac{1}{e}) = \ln (\frac{3}{e}) + 1 = \ln (3) - 1+1 = \ln (3) \\ y(\frac{1}{e}) = \frac{1}{e}\ln (3.\frac{1}{e}) = \frac{1}{e}&...