r(u,v)=⟨3cos u,3sen u,v⟩ para 0≤u≤π2,0≤v≤3\bold{r}(u, v) = \lang 3 cos\; u, 3 sen\; u, v \rang\;\;\text{para}\;\; 0 \le u \le \frac{\pi}{2}, 0 \le v \le 3r(u,v)=⟨3cosu,3senu,v⟩para0≤u≤2π,0≤v≤3