for those who are good in math this is a question for you?

Question

im learning about matrices right now and my question is if im adding matrices and one matrix is a 2x2 and the second is a 3x3 i cant add or subtract those together because they are unlike matrices right?

Answer 1

That's correct. Matrices have to have the same 'order' (the same number of rows and columns) before they can be added or subtracted.


Doug

Answer 2

Yes.

Unless, you are not talking about the usual matrix addition or subtraction.

For example, if you define a new operator, lets call it orange_crush_05_Matrix_add, where you apply the idea of smoothing, or kernel convolution to 'transform' a bigger matrix to a smaller one, before adding them the usual way, then, you may add the 2x2 to the 3x3, getting a 2x2 matrix.
E.g. a 2x2 matrix: [10, 20; 30, 40],
and a 3x3 matrix [1,2,3; 4,5,6; 7,8,9].
Transform the 3x3 by averaging the 4 2x2 "sub-matrices" within it, [1,2; 4,5], [2,3; 5,6], [4,5; 7,8], and [5,6; 8,9], giving a transformed 2x2 matrix, [3, 4; 6, 7].
Adding these two 2x2 matrices give [13, 24; 36, 47].

Anyone can simply define any operator and find out its properties, and hopefully usefulness.

Answer 3

yeah its rite ... u cant add or subtract two matrics those arent identical ... that is to add or subtract two matrices the no of rows and columns of the two matrices should be same ...
in case of multiplication the no of columns of the first matrix must be equal to the no of rows of the second matrix ..
say for example u can multiply two matricex of 2*3 nd 3*4 but u cant multiply matrices of 2*2 nd 3*2

Answer 4

Yes, you are right that you cannot add or subtract the two matrices because they have different dimensions. Note that you do not have a corresponding number to add or subtract to the corresponding space for an answer in the final matrix.

Answer 5

Your right because it's impossible to add 2X2 matrice with
3X3 matrice. To add two or more matrices you must have
the same dimension for your matrices.
Add 2X2 matrice with 2X2 matrice
Add 3X3 matrice with 3X3 matrice
Add 4X4 matrice with 4X4 matrice
etc,...

To add two matrices of same dimension we add component
by component. The final matrice will be the same dimension
that the 2 first matrices.

Example: matrice A (2X2) + matrice B (2X2) = matrice C (2X2).

Answer 6

yes right
add & substract for matrices can be done if there is same matric size

Answer 7

yes
we can't add or subtract two matrices of different order but can muntiply them

Answer 8

right. different size matrices are like apples and pears ;-)

Answer 9

Yes you are right - they are 'incompatible' matrices.

Answer 10

Couldn't have said it better myself. (actually I could have, but that's not important right now)