[size=150][size=200]To rotate a function f(x) around the x-axis.[br]1. Enter the function. I entered [b]f(x) = -(x+1)(x-4), -1≤x≤4[/b][br]2. I created a slider by entering [b]n = slider(0,2pi,pi/180)[/b][br]3. To create the surface, enter [b]surface(f,n,xAxis)[/b][/size][/size]