# MATLAB - matrice help needed

• May 10th 2008, 09:01 PM
Dr Zoidburg
MATLAB - matrice help needed
Matrix M = A=$\displaystyle \begin{bmatrix} 1 && 3 \\ -2 && 4 \\ \end{bmatrix}$ represents a linear transformation T: $\displaystyle R^{2}$ -> $\displaystyle R^{2}$.
Let u = $\displaystyle \begin{bmatrix} 1 \\ -1 \\ \end{bmatrix}$ and v = $\displaystyle \begin{bmatrix} -2 \\ 1 \\ \end{bmatrix}$
(a) Find T(u) and T(v)
(b) Show that T (u + v) = T (u) + T (v).

I'm pretty hopeless at Matlab. I can work these out by hand: eg T(u) = $\displaystyle \begin{bmatrix} -2 \\ -6 \\ \end{bmatrix}$ (correct?(Worried)) but what commands do I use in Matlab to get this?
• May 11th 2008, 05:01 AM
CaptainBlack
Quote:

Originally Posted by Dr Zoidburg
Matrix M = A=$\displaystyle \begin{bmatrix} 1 && 3 \\ -2 && 4 \\ \end{bmatrix}$ represents a linear transformation T: $\displaystyle R^{2}$ -> $\displaystyle R^{2}$.
Let u = $\displaystyle \begin{bmatrix} 1 \\ -1 \\ \end{bmatrix}$ and v = $\displaystyle \begin{bmatrix} -2 \\ 1 \\ \end{bmatrix}$
(a) Find T(u) and T(v)
(b) Show that T (u + v) = T (u) + T (v).

I'm pretty hopeless at Matlab. I can work these out by hand: eg T(u) = $\displaystyle \begin{bmatrix} -2 \\ -6 \\ \end{bmatrix}$ (correct?(Worried)) but what commands do I use in Matlab to get this?

A*u and A*v

The default product type for Matlab is matrix product so just multiply them.

RonL