Engineering Math - Matrix

Row, Column, Index

I have been almost always confused with rows and columns of a Matrix. It is not because it is difficult concept.. it was just confusing. If you have similar problem, look at these illustration and just take a picture onto your brain and just play it back in the form of image on your brain.

When we refer to (point to) a certain elements of a Matrix, we usually use a symbol as follows. Again, I have been frequently confused with which subscription indicate Row and which one indicate a Column. Also, just take the picture of this on your brain.

Because of the difficulties of writing mathematical symbols in a plain text format, I will represent this symbol as a(i,j) in this page just for easy writing.

Example >

For a practice, let's suppose that we have a simple 3 x 3 matrix as shown below. (If you are not familiar with what 3 x 3 matrix mean, refer to Matrix Dimension page)

What is a(1,1) ? => It indicate Row 1 and Col 1 meaning '1'

What is a(2,3) ? => It indicate Row 2 and Col 3 meaning '6'

What is a(3,2) ? => It indicate Row 3 and Col 1 meaning '8'