Question

Why in the matirx, the main diagonal goes from upper left to lower right? Why not define main diagonal as the other way round?

Answer 1

@ganeshie8

Answer 2

The identity matrix is a pretty important diagonal matrix, just for fun, what happens to a vector's components if you multiply it by the identity matrix version you might suggest?

Answer 3

same, I guess

Answer 4

well there's a way to check if your guess is right or not