a/ X = 1/2*5+cos(u))
Y = cos(u)*u
Z = u*1/3*u
0 < u < 8*pi
rotacija oko z ose
b/ X = sin(3*u) X = 3*sin(v)
Y = cos(u^5) Y = v
Z = u Z = 1
0 < u < 3*pi 0 = < v < 1.5pi