Converted by
Mathematica
May 17, 2001
![[Graphics:../Images/Aula12_gr_31.gif]](../Images/Aula12_gr_31.gif)
![[Graphics:../Images/Aula12_gr_32.gif]](../Images/Aula12_gr_32.gif){kind=small}
![[Graphics:../Images/Aula12_gr_33.gif]](../Images/Aula12_gr_33.gif){kind=small}
![[Graphics:../Images/Aula12_gr_34.gif]](../Images/Aula12_gr_34.gif){kind=small}