To create a surface of revolution of a function in the xy-plane around the y-axis, follow these steps:[br][list=1][br][*] Graph your function, f(t). (in this example, f(t) = -(x-1)(x-5) )[br][*] The surface is generated using the SURFACE[ t cos(u) , f(t) , t sin(u) , t , 1 , 5 , u , 0 , 2pi ][br][/list]

Explore different functions. Use the FUNCTION[ -(x-1)(x-5) , 1 , 5 ] to restrict the domain of your function.[br]Once you create the function, changing it will automatically update your surface.