a)X=f(u) sin(u)*1*(u)*cos(2*u)
Y=g(u) 2+8*cos(6*u*6)
Z=h(u) 4
0<=u<=6*pi axe(x)
b)X=f(u) sin(u)*cos(u)*8
Y=g(u) cos(u)*3
Z=h(u) 3
0<=u<=6*pi
X=f(u) v-cos(v)*3
Y=g(u) sin(v)*8
Z=h(u) 2*v
0<=v<=6*pi