We obtain the volume of solid by using triple integrals in cylindrical coordinate (r,[math]\theta[/math],z)[br][br]volume = [math]\int\int\int dV=\int\int\int dzdrd\theta[/math][br][br]Notice that the cylindrical coordinate (r,[math]\theta[/math],z) is similar to polar coordinate (r, [math]\theta[/math] ) together with z-coordinate.[br][br]To convert cartesian coordinate to cylindrical coordinate, take note of the following formulas[br][br][size=150][math]x=rcos\theta[/math][br][math]y=rsin\theta[/math][br][math]z=z[/math][br][math]x^2+y^2=r^2[/math][br][math]0\le\theta\le2\pi[/math][/size]

Type "Example 2.26" to see the graph in app