本次共计算 1 个题目:每一题对 x 求 2 阶导数。
注意,变量是区分大小写的。\[ \begin{equation}\begin{split}【1/1】求函数\frac{(x + y)}{({x}^{2} + {y}^{2} + xy)} 关于 x 的 2 阶导数:\\\end{split}\end{equation} \]
\[ \begin{equation}\begin{split}\\解:&\\ &原函数 = \frac{x}{(x^{2} + yx + y^{2})} + \frac{y}{(x^{2} + yx + y^{2})}\\&\color{blue}{函数的第 1 阶导数:}\\&\frac{d\left( \frac{x}{(x^{2} + yx + y^{2})} + \frac{y}{(x^{2} + yx + y^{2})}\right)}{dx}\\=&(\frac{-(2x + y + 0)}{(x^{2} + yx + y^{2})^{2}})x + \frac{1}{(x^{2} + yx + y^{2})} + (\frac{-(2x + y + 0)}{(x^{2} + yx + y^{2})^{2}})y + 0\\=&\frac{-2x^{2}}{(x^{2} + yx + y^{2})^{2}} - \frac{3yx}{(x^{2} + yx + y^{2})^{2}} - \frac{y^{2}}{(x^{2} + yx + y^{2})^{2}} + \frac{1}{(x^{2} + yx + y^{2})}\\\\ &\color{blue}{函数的第 2 阶导数:} \\&\frac{d\left( \frac{-2x^{2}}{(x^{2} + yx + y^{2})^{2}} - \frac{3yx}{(x^{2} + yx + y^{2})^{2}} - \frac{y^{2}}{(x^{2} + yx + y^{2})^{2}} + \frac{1}{(x^{2} + yx + y^{2})}\right)}{dx}\\=&-2(\frac{-2(2x + y + 0)}{(x^{2} + yx + y^{2})^{3}})x^{2} - \frac{2*2x}{(x^{2} + yx + y^{2})^{2}} - 3(\frac{-2(2x + y + 0)}{(x^{2} + yx + y^{2})^{3}})yx - \frac{3y}{(x^{2} + yx + y^{2})^{2}} - (\frac{-2(2x + y + 0)}{(x^{2} + yx + y^{2})^{3}})y^{2} + 0 + (\frac{-(2x + y + 0)}{(x^{2} + yx + y^{2})^{2}})\\=&\frac{8x^{3}}{(x^{2} + yx + y^{2})^{3}} + \frac{16yx^{2}}{(x^{2} + yx + y^{2})^{3}} - \frac{6x}{(x^{2} + yx + y^{2})^{2}} + \frac{10y^{2}x}{(x^{2} + yx + y^{2})^{3}} - \frac{4y}{(x^{2} + yx + y^{2})^{2}} + \frac{2y^{3}}{(x^{2} + yx + y^{2})^{3}}\\ \end{split}\end{equation} \]你的问题在这里没有得到解决?请到 热门难题 里面看看吧!