Matrices

[WayneRooney10]

what are the matrices we need to learn by heart?? Like, the reflection matrix?? Or something. Help will be appreciated. :%)

 

[Aahmsil]

Important matrices

You need to know the matrices for:
a) Shear
b) Stretch
c) Enlargement
d) Rotation (both CW and ACW)
e) Reflection

Although reflection and rotation matrices are quite easy to derive from the standard matrice if you know how to. Otherwise you have to memorise them :O:

Cheers !!! :good:

 

[WayneRooney10]

what are the matrices??? themself for each?

 

[Aahmsil]

Confused ?!?!?!?!

I'm sorry, I didn't quite get you ? Could you please rephrase ? :unknown:

 

[WayneRooney10]

I mean, like, (0 1)
(1 0)
Does a reflection. whats for the others?

 

[Aahmsil]

Okay

I see, this topic's already been discussed

Go to: http://www.xtremepapers.me/forums/viewtopic.php?f=24&t=6857

Cheers !!! :good:

 

[burndtjamb]

My post as well as the pdf posted by Keemoman in this topic should help: viewtopic.php?f=24&t=6896

 

[WayneRooney10]

Thanks ALOT both of you

 

[cHeStEr]

Is column into row possible ..if yes how ?? Plz help !

Thanks

 

[Aahmsil]

Answer

Yes :Yahoo!:

Two matrices can be multiplied with each other even if they have different dimensions, as long as the number of columns in the first matrix is equal to the number of rows in the second matrix.

The result of the multiplication, called the product, is another matrix with the same number of rows as the first matrix and the same number of columns as the second matrix.

Cheers !!! :good:

 

[cHeStEr]

Can you pose an example please ?

 

[Aahmsil]

Example

Visit my site at: http://wazzaaap.weebly.com/igcse-mathematics.html for a few examples.

The site hasn't been perfected yet so don't expect much

Sorry but I didn't have the time to present some examples of my own here :no:

Hope the site helped !!!

Cheers !!! :good:

P.S. For better results, go through my older post in conjunction with the site or visit Wikipedia to see what they have to say

 

[cHeStEr]

Nice one
Can you show the working of the multiplication of anything like this --- || x = ?? I hope you get me .. The standing x the sleeping !!

 

[Aahmsil]

Ooops !!!

I'm afraid I don't

I would be able to help you better if you rephrase

 

[cHeStEr]

1st matrix -- 3x1
2nd matrix-- 1x2


1 matrix -- 3x1
2matrix -- 1x3


These are the two questions ... Can you help me solving them with their working please ??!!

 

[cHeStEr]

All multiplication

 

[Aahmsil]

Example

1 x 3 and 3 x 1 matrices

Matrix A
[2]
[4]
[8]

Matrix B
[3 1 7]

Calculation

[ 3 1 7 ]

[2] [2*3 2*1 2*7] [ 6 2 14]
[4] [4*3 4*1 4*7] = [12 4 28]
[8] [8*3 8*1 8*7] [24 8 56]

Cheers !!! :good:

 

[Aahmsil]

Help

1st matrix -- 3x1
2nd matrix-- 1x2


1 matrix -- 3x1
2matrix -- 1x3


These are the two questions ... Can you help me solving them with their working please ??!!

You might find this helpful: http://mathforum.org/library/drmath/view/63517.html

 

[cHeStEr]

But the second question ??

Thanks for the first one btw

 

[Aahmsil]

Example 2

But the second question ??

Thanks for the first one btw

No problem, here's the other one


Matrix A (3 x 1)

[1]
[2]
[3]

Matrix B (1 x 2)

[4 5]

Multiplication

[1] [4 5]
[2]
[3]

[1 x 4______1 x 5]
[2 x 4______2 x 5]
[3 x 4______3 x 5]

[4______5]
[8_____10]
[12____15]

Use this if you have any more doubts: http://joemath.com/applets/multmat/
It's an online matrix multiplier.

Hope that helped !!!

Good luck, do well !!!

Cheers !!! :good: