V=∫abS(x)dx V = \int_a^b S(x) dx V=∫abS(x)dx
V=2π∫abxf(x)dx V = 2\pi \int_a^b xf(x) dx V=2π∫abxf(x)dx
V=π∫x1x2f2(x)dx V = \pi \int_{x_1}^{x_2} f^2(x) dx V=π∫x1x2f2(x)dx
