Question

how to find the inverse matrix?

Answer 1

is it possible to use \[\LARGE \left[\begin{array}{ccc} 1 & 0 & 0 \\ 0 & 1 & 0 \\ 0 & 0 & 1 \end{array} \right]\]

Answer 2

when you a square matrix A (with det(a) nor zero) then you reduce the matrix
\[ (A\mid I) \]
where I is the identity matrix of the same size as A

Answer 3

uhh what does that mean?

Answer 4

okay perhaps a demo...what is the inverse for \[\huge \left[\begin{array}{ccc} 1 & 2 & 0 \\ 3 & 0 & 2 \\ 1 & 1 & 0 \end{array} \right]\]

Answer 5

OK
to find the inverse of the matrix you put, you construct the matrix
\[ \LARGE \left[\begin{array}{ccc|ccc}
1 & 2 & 0 & 1 & 0 & 0\\ 3 & 0 & 2 & 0 & 1 & 0\\
1 & 1 & 0 & 0 & 0 & 1
\end{array}\right] \]
and find the RREF form.

Answer 6

okay two questions:
1) how do you do that line in the middle?
2) do we make the left side become
1 0 0
0 1 0
0 0 1
??

Answer 7

for 1) do you want the latex code?

Answer 8

yup

Answer 9

\left[\begin{array}{ccc|ccc}
\end{array}\right]

Answer 10

"\begin{array}{ccc|ccc}
\end{array}"

Answer 11

\verb"\begin{array}{ccc|ccc}
\end{array}"

Answer 12

begin{array}{ccc|ccc}
end{array}

Answer 13

finally

Answer 14

for 2) yes. when and if you get I on the left side, if the matrix has inverse the it should appear on the right side

Answer 15

ohhh {ccc|ccc}

Answer 16

how can i make the second row 0 again?

Answer 17

i dont' understand

Answer 18

i have to make 3 become 0 right? so do i do -3R1 + r2?

Answer 19

yes
\[ (-3)R_1+R_2\to R_2 \]

Answer 20

hmm ok i think im imagining it now thanks

Answer 21

ok
you're welcome

Answer 22

Inverse of matrix calculator: http://www.emathhelp.net/calculators/inverse-of-matrix-calculator?i=%5B%5B1%2C2%2C0%5D%2C%5B3%2C0%2C2%5D%2C%5B1%2C1%2C0%5D%5D