Go confidently in the direction of your dreams. Live the life you've imagined. 题目 设曲线 \(y = \tfrac{1}{x}\) (1\(\leq\)x\(\leq\)+\(\infty\)) 与X 轴之间的区域为D. 求D绕X轴旋转一周的旋转体的体积V和面积A. 图形如下 画出图形容易计算体积 \[ V = \begin{aligned} \int_1 ^{+\infty} \pi ( \tfrac{1}{x}