Matrices

[shan2391]

GUys i m confused about the inverse if we hav 2 know matrices 2by2 e.g A and B and an unknown Matrix X.
SO if we have an eq AX=B
would we do X=(Ainverse)8B       or X=B*(Ainverse)
and when we have to find B*Ainverse wat do v do?

[Ghost Of Highbury]

it depends on the order of the matrix A and B

for e.g
if the question says....(1  2) * X = (5  6  7)
                              (3  4)          (8  9  2)

then for that X = (1  2)  *  (5  6  7)
                        (3  4)     ( 8  9  2)
this is because the no. of colums of the first matrix = the no. of rows of the second matrix
=>                             (2)                                 =            (2)
first matrix = (1  2)
                   (3  4)

second matrix = (5  6  7)
                       (8  9  2)

Good luck

[Ghost Of Highbury]

u cannot do the other way i.e
(5  6  7)  *   (1  2)
(8  9  2)      ( 3  4)

because the no. of columns of the first matrix (3) is not equal to the no. of rows of the second matrix (2)

[shan2391]

wat if both have the same order e.g 2by2

[Ghost Of Highbury]

then it doesn't matter how u multiply them...