Help with matrices problem

Pamplemousse19

I've an assignment due for tomorrow so I'd be grateful if anyone could help me fairly soon! Here's the Q: Find a 2 x 2 matrix such that AC=4C - B when A and B are given.

D-Generate

It has been a while but...

4C - AC = B
[4-A]C = B
C = (4-A)^-1B

where 4 is [4 0;0 4]

Thomas_S_Hunterson

Just to make that last line a bit less ambiguous:

[latex]\displaystyle C = (4-A)^{-1} B[/latex]

RolandIRL

would there also need to be the 2x2 identity matrix after the 4 in the last line?

Michael Collins

whiteman19 wrote: »

would there also need to be the 2x2 identity matrix after the 4 in the last line?

There sure would, good spot.

D-Generate

Ah yeah but I said
4 = [4 0; 0 4]
so same thing really.

How does one put in the Latex type stuff?

[latex]\[
4 =
\left[ {\begin{array}{cc}
4 & 0 \\
0 & 4 \\
\end{array} } \right]
\][/latex]

Thomas_S_Hunterson

Put it in latex bbcode tags:

[latex] y = x^2 [/latex]

/edit: ok it's actually parsing the contents of a code box...this is a bug.

Put your latex code between latex tags as follows but without the dashes [-latex] and [-/latex]

r3nu4l

To avoid the latex tags being coded do the following...

[noparse][noparse][latex] y = x^2 [/latex][/noparse][/noparse]

then you get this:

[noparse][latex] y = x^2 [/latex][/noparse]

RolandIRL

D-Generate wrote: »

Ah yeah but I said
4 = [4 0; 0 4]
so same thing really.

How does one put in the Latex type stuff?

[latex]\[
4 =
\left[ {\begin{array}{cc}
4 & 0 \\
0 & 4 \\
\end{array} } \right]
\][/latex]

didn't see your edit just saw the post before mine

LeixlipRed

Is that the solution to the latex issue then or what? I'm not in any way a techie. If it needs to be brought up over in moderator land soneone PM and I'll do so.