# Homework Help: Which of the folllowing transformations are linear? how can u tell?

1. Nov 26, 2005

### mr_coffee

http://img499.imageshack.us/img499/9875/untitled1copy0oi.jpg [Broken]

Hello everyone i'm not looking for someoene to tell me the answer, but i'm really confused on how you can tell if somthing is a linear stransformation or not? I'm not understand what operations i'm suppose to go through to find this out, any help would be great! thanks!
The image is above which explains the problem!

Last edited by a moderator: May 2, 2017
2. Nov 26, 2005

### matt grime

If you cannot verify the axioms of linearity, try to find a counter example. Ie try to show L(x+y)=L(x)+L(y), and L(ky)=kL(y), and if that's impossible, show why (simply find a single counter example)

3. Nov 26, 2005

### HallsofIvy

Checking the DEFINITION of "Linear Transformation" would seem like a good idea. As I recall, the definition requires that
L(u+ v)= L(u)+ L(v) and L(av)= aL(v) where u and v are vectors (your examples all involve 2 or 3 dimensional vectors) and a is a number.