a)
X= sin(u^4)*5+2*cos(u)*3*cos(u)
Y= u^2*sin(u)
Z= 1
7<= u <= 2*pi
b)
X= cos(u)*2*sin(u)
Y= u
Z= 0.5
0 <= u <= 2*pi
X= sin(v)*cos(v)
Y= 3
Z= v
0 <= v <= 2*pi
