Risolvere SENZA la tecnica X SOSTITUZIONE.
Spiegare e argomentare i passaggi.
$ \int_{-1}^4 \frac{x}{\sqrt{x+5}} \, dx =$
$ = \int_{-1}^4 \frac{x+5-5}{\sqrt{x+5}} \, dx =$
$ = \int_{-1}^4 \frac{x+5}{\sqrt{x+5}} -\frac{ 5}{\sqrt{x+5}} \, dx =$
$ = \int_{-1}^4 (x+5)^{\frac{1}{2}} - 5(x+5)^{-\frac{1}{2}} \, dx =$
$ = \left. \frac{2}{3} (x+5)^{\frac{3}{2}} -5 \cdot 2(x+5)^{\frac{1}{2}} \right|_{-1}^4 =$
$ = \left. \frac{2}{3} (x+5)\cdot (x+5)^{\frac{1}{2}} -10(x+5)^{\frac{1}{2}} \right|_{-1}^4 =$
$ = \left. (x+5)^{\frac{1}{2}} (\frac{2}{3}(x+5)-10) \right|_{-1}^4 =$
$ = \left. (x+5)^{\frac{1}{2}} \frac{2}{3}(x-10) \right|_{-1}^4 =$
$ = -12 + \frac{44}{3} = \frac{8}{3} $