Please please help :)

Consider the surface S described by S={x2+y2=(5z)2,0z5}. Parameterize S via the vector r(u,v). A sketch is very helpful. Hint: Let u=z. The x2+y2 part can be expressed using sines and cosines in variable v, but you must pay careful attention to the radius function of the resulting circle. The bounds for u and v are an important part of the parameterized description