MATLAB - matrice help needed

Dr Zoidburg · #1 $Old$ May 10th, 2008, 11:01 PM

Matrix M = A= $\begin{bmatrix} 1 && 3 \\ -2 && 4 \\ \end{bmatrix}$ represents a linear transformation T: $R^{2}$ -> $R^{2}$ .
Let u = $\begin{bmatrix} 1 \\ -1 \\ \end{bmatrix}$ and v = $\begin{bmatrix} -2 \\ 1 \\ \end{bmatrix}$
(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) = $\begin{bmatrix} -2 \\ -6 \\ \end{bmatrix}$ (correct?

) but what commands do I use in Matlab to get this?

CaptainBlack · #2 $Old$ May 11th, 2008, 07:01 AM

Quote:

Originally Posted by Dr Zoidburg $View Post$

Matrix M = A= $\begin{bmatrix}1 && 3 \\-2 && 4 \\\end{bmatrix}$ represents a linear transformation T: $R^{2}$ -> $R^{2}$ .
Let u = $\begin{bmatrix}1 \\-1 \\\end{bmatrix}$ and v = $\begin{bmatrix}-2 \\1 \\\end{bmatrix}$
(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) = $\begin{bmatrix}-2 \\-6 \\\end{bmatrix}$ (correct?

) 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