(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

DB+CA^T-2A

D=3row x 3col

B=2x2

C=2row X 3col

A=3row X 2col

3. The attempt at a solution

It is my understanding that a row of a matrix is horizontal variables and a column is the vertical variables. And for multiplication of two matrices you need the colums of the first matrix to be equal to the number of rows in the second matrix.

so DB= (D3x3)x(A2x2) so therefore DB is undefined.

The transpose of A3x2->A2x3 so CA^T = (C2x3) x (A2x3) Which is also undefined.

So does this then mean that the answer for DB+CA^T-2A is just undefined or is the answer -2A? I am unsure what the answer is or how to word it correctly

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Addition of undefined matrices

**Physics Forums | Science Articles, Homework Help, Discussion**