2.

>> array=[3;6]

array =

     3
     6

>> eye2=eye(2)

eye2 =

     1     0
     0     1

>> matrix = [eye2 array]

matrix =

     1     0     3
     0     1     6

>> size(matrix)

ans =

     2     3

>> x = 0
for i = 0:25
x = x + i;
end
x =
0
>> x
x =
325
%%Notice that if we leave off the semicolon above we will see all the partial sums.

>> sum(0:25)
ans =
325

>> sin(pi/4)
ans =
0.7071
>> sin([0 pi/4 pi/2 3*pi/4 pi])
ans =
0 0.7071 1.0000 0.7071 0.0000