Matrice question

• Nov 25th 2012, 08:56 AM
Petrus
Matrice question
Hi idk if i have missunderstand but serious i thought u cant a•b on this but they did in the answer....how do i do A•B?!?!?!
• Nov 25th 2012, 09:15 AM
Plato
Re: Matrice question
Quote:

Originally Posted by Petrus
Hi idk if i have missunderstand but serious i thought u cant a•b on this but they did in the answer....how do i do A•B?!?!?!

$\displaystyle A_{2,2}\cdot B_{2,3}=C_{2,3}$.

$\displaystyle \left( {\begin{array}{rr} 3 & { - 5} \\ 2 & 3 \\ \end{array} } \right) \cdot \left( {\begin{array}{rrr} { - 7} & 4 & 0 \\ 2 & { - 5} & 1 \\ \end{array} } \right) = \left( {\begin{array}{rrr} { - 31} & {37} & ? \\ ? & ? & ? \\ \end{array} } \right)$
• Nov 25th 2012, 09:21 AM
Petrus
Re: Matrice question
Facit says Attachment 25926
• Nov 25th 2012, 09:32 AM
Plato
Re: Matrice question
Quote:

Originally Posted by Petrus
Facit says

I don't have a clue what you mean by?
This is an Englsh language forum.
The OP contains a very poor image not in English.
But it is clear what the matrices $\displaystyle A~\&~B$ equal.

The OP then asks how to find $\displaystyle A\cdot B~.$
• Nov 25th 2012, 09:36 AM
Petrus
Re: Matrice question
Sorry i did missunderstand the quest and ut answer was not really worthless u did just teach me u can multiplicate it:)! Ty alot that Will help if i get any quest like that:) anoying that My book on swedish:/ cant change it
edit: what does OP means?
• Nov 25th 2012, 09:56 AM
MarkFL
Re: Matrice question
Hello Petrus,

OP can mean either "original post" (the first post) or "original poster" (the person who began the topic).

It will be easier for people to give you help if you take the time to translate the problem into English and preferably typeset the mathematical statements in the problem using $\displaystyle \LaTeX$.

Also, try to refrain from using "text-talk" abbreviations in your posts. These are fine for informal one-on-one messages in private, but when trying to communicate publicly, you should use full words, so that those who aren't familiar with these type of abbreviations aren't left wondering what you are saying.