I have to calculate and plot the volume of a cicloid where a equals 27. Now, the assisstant gave us the supposed code to work with, as most were having trouble with it. Here it is:

with(plots)

plot3d(27*(t-sin(t)),sqrt((27*(1-cos(t)))^2)*cos(s),sqrt((27*(1-cos(t)))^2)*sin(s),t=0..2*Pi,s=0..2*Pi);

However, this gives me the following error when trying to execute:

Error, (in plot3d) bad range arguments: ((27-27*cos(t...