<

Question: Plotting help intersection 3 surfaces

Given 3 surfaces:

x^2+y^2=1,z=0(the xy base plane) and z=1-x^2

To plot these I suggested to use cylindrical coordiates knowing x=r*cos(t) and y=r*sin(t)

Which leads to z=1-r^2*cos^2(t)

However i got problems knowing how to plot this object and dearly ask for help.

plothelp.mw

Please Wait...