Find the inverse of the Matrix using elementary transformation

Question

diyadiya · Answer

$$\begin{bmatrix}
2 & 0 &-1 \ 
 5& 1 &0 \ 
0 &  1& 3
\end{bmatrix}$$

anonymous · Answer

its a long process...  :)

diyadiya · Answer

is there any easy way ? because i usually end up with wrong answers (actually i dont get the right answer )

anonymous · Answer

did you try the method imran posted?

diyadiya · Answer

Minors & cofactors ?

anonymous · Answer

yeah that one

anonymous · Answer

yea ...its also same long method...  :)

diyadiya · Answer

But i cant use it here

anonymous · Answer

are you supposed to do this
$$\begin{bmatrix}
2 & 0 &-1 \ 
 5& 1 &0 \ 
0 &  1& 3
\end{bmatrix}\times \begin{bmatrix}
a_{11} & a_{12} &a_{13} \ 
 a_{21}& a_{22} &a_{23}\ 
a_{31} &  a_{32}& a_{33}
\end{bmatrix}=\begin{bmatrix}
1 & 0 & 0\ 
 0& 1 &0 \ 
0 &  0& 1
\end{bmatrix}$$

diyadiya · Answer

Yes

anonymous · Answer

oh man i remember this. it is a real pain. you write one your matrix next to the identity, and then keep track as you go to make turn your matrix in to the identity. a decent explanation is here, but it takes for flippin ever http://www.purplemath.com/modules/mtrxinvr.htm

diyadiya · Answer

Lol the thing is i hardly get the right answer 

I'll check it out Thankyou Satellite :)

turingtest · Answer

Here's a rather thorough list of ways to find inverse matrices. I like the one sat mentioned, illustrated in examples 1, 2, and 3 in the link: http://tutorial.math.lamar.edu/Classes/LinAlg/FindingInverseMatrices.aspx

diyadiya · Answer

OK thankyou :) i'll check it out !! :)