本次共计算 2 个题目:每一题对 x 求 4 阶导数。
注意,变量是区分大小写的。\[ \begin{equation}\begin{split}【1/2】求函数e^{lgx} 关于 x 的 4 阶导数:\\\end{split}\end{equation} \]
\[ \begin{equation}\begin{split}\\解:&\\ &\color{blue}{函数的第 1 阶导数:}\\&\frac{d\left( e^{lgx}\right)}{dx}\\=&e^{lgx}lg\\=&lge^{lgx}\\\\ &\color{blue}{函数的第 2 阶导数:} \\&\frac{d\left( lge^{lgx}\right)}{dx}\\=&lge^{lgx}lg\\=&l^{2}g^{2}e^{lgx}\\\\ &\color{blue}{函数的第 3 阶导数:} \\&\frac{d\left( l^{2}g^{2}e^{lgx}\right)}{dx}\\=&l^{2}g^{2}e^{lgx}lg\\=&l^{3}g^{3}e^{lgx}\\\\ &\color{blue}{函数的第 4 阶导数:} \\&\frac{d\left( l^{3}g^{3}e^{lgx}\right)}{dx}\\=&l^{3}g^{3}e^{lgx}lg\\=&l^{4}g^{4}e^{lgx}\\ \end{split}\end{equation} \]\[ \begin{equation}\begin{split}【2/2】求函数e^{lg(x)} 关于 x 的 4 阶导数:\\\end{split}\end{equation} \]
\[ \begin{equation}\begin{split}\\解:&\\ &\color{blue}{函数的第 1 阶导数:}\\&\frac{d\left( e^{lg(x)}\right)}{dx}\\=&\frac{e^{lg(x)}}{ln{10}(x)}\\=&\frac{e^{lg(x)}}{xln{10}}\\\\ &\color{blue}{函数的第 2 阶导数:} \\&\frac{d\left( \frac{e^{lg(x)}}{xln{10}}\right)}{dx}\\=&\frac{-e^{lg(x)}}{x^{2}ln{10}} + \frac{e^{lg(x)}}{xln{10}(x)ln{10}} + \frac{e^{lg(x)}*-0}{xln^{2}{10}}\\=&\frac{-e^{lg(x)}}{x^{2}ln{10}} + \frac{e^{lg(x)}}{x^{2}ln^{2}{10}}\\\\ &\color{blue}{函数的第 3 阶导数:} \\&\frac{d\left( \frac{-e^{lg(x)}}{x^{2}ln{10}} + \frac{e^{lg(x)}}{x^{2}ln^{2}{10}}\right)}{dx}\\=&\frac{--2e^{lg(x)}}{x^{3}ln{10}} - \frac{e^{lg(x)}}{x^{2}ln{10}(x)ln{10}} - \frac{e^{lg(x)}*-0}{x^{2}ln^{2}{10}} + \frac{-2e^{lg(x)}}{x^{3}ln^{2}{10}} + \frac{e^{lg(x)}}{x^{2}ln{10}(x)ln^{2}{10}} + \frac{e^{lg(x)}*-2*0}{x^{2}ln^{3}{10}}\\=&\frac{2e^{lg(x)}}{x^{3}ln{10}} - \frac{3e^{lg(x)}}{x^{3}ln^{2}{10}} + \frac{e^{lg(x)}}{x^{3}ln^{3}{10}}\\\\ &\color{blue}{函数的第 4 阶导数:} \\&\frac{d\left( \frac{2e^{lg(x)}}{x^{3}ln{10}} - \frac{3e^{lg(x)}}{x^{3}ln^{2}{10}} + \frac{e^{lg(x)}}{x^{3}ln^{3}{10}}\right)}{dx}\\=&\frac{2*-3e^{lg(x)}}{x^{4}ln{10}} + \frac{2e^{lg(x)}}{x^{3}ln{10}(x)ln{10}} + \frac{2e^{lg(x)}*-0}{x^{3}ln^{2}{10}} - \frac{3*-3e^{lg(x)}}{x^{4}ln^{2}{10}} - \frac{3e^{lg(x)}}{x^{3}ln{10}(x)ln^{2}{10}} - \frac{3e^{lg(x)}*-2*0}{x^{3}ln^{3}{10}} + \frac{-3e^{lg(x)}}{x^{4}ln^{3}{10}} + \frac{e^{lg(x)}}{x^{3}ln{10}(x)ln^{3}{10}} + \frac{e^{lg(x)}*-3*0}{x^{3}ln^{4}{10}}\\=&\frac{-6e^{lg(x)}}{x^{4}ln{10}} + \frac{11e^{lg(x)}}{x^{4}ln^{2}{10}} - \frac{6e^{lg(x)}}{x^{4}ln^{3}{10}} + \frac{e^{lg(x)}}{x^{4}ln^{4}{10}}\\ \end{split}\end{equation} \]你的问题在这里没有得到解决?请到 热门难题 里面看看吧!