导数:\left(x\ln x\right)'=\ln x+1 单调性:在\displaystyle\left(\,0\,,\,\frac{1}{e}\,\right]上单调递减,在\displaystyle\left[\,\frac{1}{e}\,,\,+\infty\,\right)上单调递增 极值点坐标:\displaystyle\left(\,\frac{1}{e}\,,\,-\frac{1}{e}\,\right) y=x·sinx 图像: 定义...