octave:2> A=fix(100*rand(3,4)-50)
A =

  -44    5  -30    8
   39  -28    9   16
    2   -1  -13  -42

octave:3> % questao 1 folha 2
octave:3> % A transposto
octave:3> %(a)
octave:3> (A')'
ans =

  -44    5  -30    8
   39  -28    9   16
    2   -1  -13  -42

octave:4> A
A =

  -44    5  -30    8
   39  -28    9   16
    2   -1  -13  -42

octave:5> S=A*A' 
S =

   2925  -1998    -39
  -1998   2642   -683
    -39   -683   1938

octave:6> clear
octave:7> %exercicio 2
octave:7> A=fix(100*rand(4,4)-50); B=fix(100*rand(4,4)-50);
octave:8> A
A =

   -7   28  -44  -20
   40   19  -40  -34
   12  -37   28   -0
   20   44   11  -38

octave:9> B
B =

   -1  -13  -43   -0
   42   48    3    8
   18  -18  -48    4
   27  -12  -41    6


octave:10> (A*B)'==A'*B'
ans =

   0   0   0   0
   0   0   0   0
   0   0   0   0
   0   0   0   0

octave:11> (A*B)'==B'*A'
ans =

   1   1   1   1
   1   1   1   1
   1   1   1   1
   1   1   1   1

octave:12> A^5*B^5== (A*B)^5
ans =

   0   0   0   0
   0   0   0   0
   0   0   0   0
   0   0   0   0

octave:13> all(all(A^5*B^5== (A*B)^5))
ans = 0
octave:14> %exerc 5 folha 2
octave:14> I3=eye(3);
octave:15> E=I3; E(3,1)=-2
E =

   1   0   0
   0   1   0
  -2   0   1

octave:16> P=I3; P(1,:)=I3(2,:); P(2,:)=I3(1,:)
P =

   0   1   0
   1   0   0
   0   0   1

octave:17> D=I3; D(2,2)=2
D =

   1   0   0
   0   2   0
   0   0   1

octave:18> A=[ 3 2 -1; 8 3 3; -2 -1 -7]
A =

   3   2  -1
   8   3   3
  -2  -1  -7

octave:19> D*A
ans =

    3    2   -1
   16    6    6
   -2   -1   -7

octave:20> E*A
ans =

   3   2  -1
   8   3   3
  -8  -5  -5

octave:21> P*A
ans =

   8   3   3
   3   2  -1
  -2  -1  -7

octave:22> A
A =

   3   2  -1
   8   3   3
  -2  -1  -7

octave:23> A*P
ans =

   2   3  -1
   3   8   3
  -1  -2  -7

octave:24> A*D
ans =

   3   4  -1
   8   6   3
  -2  -2  -7

octave:25> A
A =

   3   2  -1
   8   3   3
  -2  -1  -7

octave:26> A*E
ans =

    5    2   -1
    2    3    3
   12   -1   -7

octave:27> inv(P)
ans =

   0   1   0
   1   0   0
   0   0   1

octave:28> D
D =

   1   0   0
   0   2   0
   0   0   1

octave:29> inv(D)
ans =

   1.00000   0.00000   0.00000
   0.00000   0.50000   0.00000
   0.00000   0.00000   1.00000

octave:30> E
E =

   1   0   0
   0   1   0
  -2   0   1

octave:31> inv(E)
ans =

   1   0   0
   0   1   0
   2   0   1

octave:32> A^(-1)
ans =

  -0.375000   0.312500   0.187500
   1.041667  -0.479167  -0.354167
  -0.041667  -0.020833  -0.145833


octave:34> %exercicio 6
octave:34> I3=eye (3);
octave:35> E21=I3; E21(2,:)=I3(2,:)+(-2)*I3(1,:)
E21 =

   1   0   0
  -2   1   0
   0   0   1

octave:36> E31=I3; E31(3,:)=I3(3,:)+(-1)*I3(1,:)
E31 =

   1   0   0
   0   1   0
  -1   0   1

octave:37> E32=I3; E32(3,:)=I3(3,:)+2*I3(2,:)
E32 =

   1   0   0
   0   1   0
   0   2   1

octave:38> A=[5 1 -3; 8 0 -4; 3 0 10]
A =

    5    1   -3
    8    0   -4
    3    0   10

octave:39> E21*A
ans =

    5    1   -3
   -2   -2    2
    3    0   10

octave:40> diary off