Question

Is the matrix operation CA possible? If so how would I solve that since the matrix's are different dimensions?

Answer 1

http://assets.openstudy.com/updates/attachments/515c4ceee4b0507ceba37899-e.mccormick-1369021610530-matrixmultiplication.png

Answer 2

My general purpose matrix multiplication answer. =)

Answer 3

thanks! that makes sense but how would i solve it if matrix A is a 3x3 and matrix C is just [1 3 5]? @e.mccormick

Answer 4

Well, you have a 3x3 and a 1x3. They are multiplied as CA, so:

1x3 3x3

The threes in the center match, so it will be able to be done. The answer will be a 1x3.

Answer 5

\(\begin{bmatrix}
1 & 3 & 5
\end{bmatrix}

\begin{bmatrix}
2 & -1 & 0 \\
0 & 5 & 0.3 \\
1 & 4 & 10
\end{bmatrix}\)

Answer 6

\(\begin{bmatrix}
x_1 & x_2 & x_3
\end{bmatrix}

\begin{bmatrix}
a & b & c \\
d & e & f \\
g & h & i
\end{bmatrix}\implies \)

\(\begin{bmatrix}
x_1 a + x_2 d + x_3 g&

x_1 b + x_2 e + x_3 h&

x_1 c + x_2 f + x_3 i
\end{bmatrix}
\)

See how the first matrix contributes to the rows and the second cotributes to the columns?

Answer 7

Because there is only one row in the answer, it is not as obvious. But every row in the first matrix is in every row of the answer.

Every column of the second matrix is in every column of the answer. So the first column of the second matrix is adg. Note that all three of those are in the first column of the answer!

Answer 8

Oh, and if you want to know how I am typing in matrices... it is:

\(\huge
\bbox[3pt,#FF00ff, border:2px solid #FF0000]{
\bbox[3pt,#B600ff, border:2px solid #FF4900]{
\bbox[3pt,#6D00ff, border:2px solid #FF9200]{
\bbox[3pt,#2400ff, border:2px solid #FFDB00]{
\bbox[3pt,#0000ff, border:2px solid #FFff00]{
\bbox[3pt,#0049ff, border:2px solid #B6ff00]{
\bbox[3pt,#0092ff, border:2px solid #6Dff00]{
\bbox[3pt,#00DBff, border:2px solid #00ff00]{
\bbox[3pt,#00ffff, border:2px solid #00ff49]{
\bbox[3pt,#00ffDB, border:2px solid #00ffDB]{
\bbox[3pt,#00ff49, border:2px solid #00ffff]{
\bbox[3pt,#00ff00, border:2px solid #00DBff]{
\bbox[3pt,#6Dff00, border:2px solid #0092ff]{
\bbox[3pt,#B6ff00, border:2px solid #0049ff]{
\bbox[3pt,#FFff00, border:2px solid #0000ff]{
\bbox[3pt,#FFDB00, border:2px solid #2400ff]{
\bbox[3pt,#FF9200, border:2px solid #6D00ff]{
\bbox[3pt,#FF4900, border:2px solid #B600ff]{
\bbox[3pt,#FF0000, border:2px solid #FF00ff]{
\bbox[3pt,white,border:2px solid #000000]{\rlap{\;\huge\color{magenta}{\LaTeX}}\color{black}{\LaTeX}}
}}}}}}}}}}}}}}}}}}}\)

We get a little silly over in the \(\LaTeX\) part of OS.
http://openstudy.com/study#/groups/LaTeX%20Practicing!%20%3A%29

Answer 9

is the answer [7 34 50.9] ?

Answer 10

Yep.

Answer 11

wow thanks!! :)

Answer 12

Well, you are getting the hang of it. That makes all the difference. Oh, and they also call this part of math Linear Algebra. All the matrix stuff.

Answer 13

thank you it really means a lot to me :)

Answer 14

Wait until you find out the world of things you can solve with determinants. Makes later math so simple at times.

Answer 15

cant wait :p