捕捉説明

$${y = xe^{x+1}}$$

$$\begin{eqnarray*} e^{x+1}&=&e^t,\qquad(t=x+1)\\ \frac{d}{dx}e^{x+1} &=&\frac... ...ft\{\frac{d}{dx}(x+1)\right\}\\ &=&e^t\times 1\\ &=& e^{x+1} \end{eqnarray*}$$