本次共计算 1 个题目:每一题对 x 求 3 阶导数。
注意,变量是区分大小写的。\[ \begin{equation}\begin{split}【1/1】求函数\frac{xsin(x)}{(1 + x)} 关于 x 的 3 阶导数:\\\end{split}\end{equation} \]
\[ \begin{equation}\begin{split}\\解:&\\ &原函数 = \frac{xsin(x)}{(x + 1)}\\&\color{blue}{函数的第 1 阶导数:}\\&\frac{d\left( \frac{xsin(x)}{(x + 1)}\right)}{dx}\\=&(\frac{-(1 + 0)}{(x + 1)^{2}})xsin(x) + \frac{sin(x)}{(x + 1)} + \frac{xcos(x)}{(x + 1)}\\=&\frac{-xsin(x)}{(x + 1)^{2}} + \frac{sin(x)}{(x + 1)} + \frac{xcos(x)}{(x + 1)}\\\\ &\color{blue}{函数的第 2 阶导数:} \\&\frac{d\left( \frac{-xsin(x)}{(x + 1)^{2}} + \frac{sin(x)}{(x + 1)} + \frac{xcos(x)}{(x + 1)}\right)}{dx}\\=&-(\frac{-2(1 + 0)}{(x + 1)^{3}})xsin(x) - \frac{sin(x)}{(x + 1)^{2}} - \frac{xcos(x)}{(x + 1)^{2}} + (\frac{-(1 + 0)}{(x + 1)^{2}})sin(x) + \frac{cos(x)}{(x + 1)} + (\frac{-(1 + 0)}{(x + 1)^{2}})xcos(x) + \frac{cos(x)}{(x + 1)} + \frac{x*-sin(x)}{(x + 1)}\\=&\frac{2xsin(x)}{(x + 1)^{3}} - \frac{2sin(x)}{(x + 1)^{2}} - \frac{2xcos(x)}{(x + 1)^{2}} + \frac{2cos(x)}{(x + 1)} - \frac{xsin(x)}{(x + 1)}\\\\ &\color{blue}{函数的第 3 阶导数:} \\&\frac{d\left( \frac{2xsin(x)}{(x + 1)^{3}} - \frac{2sin(x)}{(x + 1)^{2}} - \frac{2xcos(x)}{(x + 1)^{2}} + \frac{2cos(x)}{(x + 1)} - \frac{xsin(x)}{(x + 1)}\right)}{dx}\\=&2(\frac{-3(1 + 0)}{(x + 1)^{4}})xsin(x) + \frac{2sin(x)}{(x + 1)^{3}} + \frac{2xcos(x)}{(x + 1)^{3}} - 2(\frac{-2(1 + 0)}{(x + 1)^{3}})sin(x) - \frac{2cos(x)}{(x + 1)^{2}} - 2(\frac{-2(1 + 0)}{(x + 1)^{3}})xcos(x) - \frac{2cos(x)}{(x + 1)^{2}} - \frac{2x*-sin(x)}{(x + 1)^{2}} + 2(\frac{-(1 + 0)}{(x + 1)^{2}})cos(x) + \frac{2*-sin(x)}{(x + 1)} - (\frac{-(1 + 0)}{(x + 1)^{2}})xsin(x) - \frac{sin(x)}{(x + 1)} - \frac{xcos(x)}{(x + 1)}\\=&\frac{-6xsin(x)}{(x + 1)^{4}} + \frac{6sin(x)}{(x + 1)^{3}} + \frac{6xcos(x)}{(x + 1)^{3}} - \frac{6cos(x)}{(x + 1)^{2}} + \frac{3xsin(x)}{(x + 1)^{2}} - \frac{3sin(x)}{(x + 1)} - \frac{xcos(x)}{(x + 1)}\\ \end{split}\end{equation} \]你的问题在这里没有得到解决?请到 热门难题 里面看看吧!