本次共计算 1 个题目:每一题对 x 求 4 阶导数。
注意,变量是区分大小写的。\[ \begin{equation}\begin{split}【1/1】求函数x*3sin(x)cos(x) 关于 x 的 4 阶导数:\\\end{split}\end{equation} \]
\[ \begin{equation}\begin{split}\\解:&\\ &原函数 = 3xsin(x)cos(x)\\&\color{blue}{函数的第 1 阶导数:}\\&\frac{d\left( 3xsin(x)cos(x)\right)}{dx}\\=&3sin(x)cos(x) + 3xcos(x)cos(x) + 3xsin(x)*-sin(x)\\=&3sin(x)cos(x) + 3xcos^{2}(x) - 3xsin^{2}(x)\\\\ &\color{blue}{函数的第 2 阶导数:} \\&\frac{d\left( 3sin(x)cos(x) + 3xcos^{2}(x) - 3xsin^{2}(x)\right)}{dx}\\=&3cos(x)cos(x) + 3sin(x)*-sin(x) + 3cos^{2}(x) + 3x*-2cos(x)sin(x) - 3sin^{2}(x) - 3x*2sin(x)cos(x)\\=&6cos^{2}(x) - 6sin^{2}(x) - 12xsin(x)cos(x)\\\\ &\color{blue}{函数的第 3 阶导数:} \\&\frac{d\left( 6cos^{2}(x) - 6sin^{2}(x) - 12xsin(x)cos(x)\right)}{dx}\\=&6*-2cos(x)sin(x) - 6*2sin(x)cos(x) - 12sin(x)cos(x) - 12xcos(x)cos(x) - 12xsin(x)*-sin(x)\\=&-36sin(x)cos(x) - 12xcos^{2}(x) + 12xsin^{2}(x)\\\\ &\color{blue}{函数的第 4 阶导数:} \\&\frac{d\left( -36sin(x)cos(x) - 12xcos^{2}(x) + 12xsin^{2}(x)\right)}{dx}\\=&-36cos(x)cos(x) - 36sin(x)*-sin(x) - 12cos^{2}(x) - 12x*-2cos(x)sin(x) + 12sin^{2}(x) + 12x*2sin(x)cos(x)\\=&-48cos^{2}(x) + 48sin^{2}(x) + 48xsin(x)cos(x)\\ \end{split}\end{equation} \]你的问题在这里没有得到解决?请到 热门难题 里面看看吧!