# How to prove subspace here

1. Dec 17, 2008

### transgalactic

i know that in order to prove that one group of vectors are a part of another
i need to stack them up

i did row reduction and i dont know how to extract a vector for the group

http://img384.imageshack.us/img384/2546/55339538nk4.gif [Broken]

this came from this question part 2

http://img116.imageshack.us/img116/1152/25587465vv2.gif [Broken]

in the U group i have equations with "k"
i dont know what vectors to take?

Last edited by a moderator: May 3, 2017
2. Dec 17, 2008

### buffordboy23

Have you tried using orthogonality? If the vectors span R^(3), then they must be linearly independent; how can you show that two vectors are perpendicular?

3. Dec 17, 2008

### transgalactic

http://img408.imageshack.us/img408/2364/89390838kq8.gif [Broken]

Last edited by a moderator: May 3, 2017
4. Dec 17, 2008

### transgalactic

this last part is row reduction question..

i dont know how to build the build matrix

5. Dec 17, 2008

### HallsofIvy

Staff Emeritus
What set is it that you are trying to prove is a subspace?

6. Dec 17, 2008

### transgalactic

i am trying to prove that u(k1) is a subset of v(k2)

7. Dec 17, 2008

### transgalactic

how to solve the second part?

8. Dec 17, 2008

### buffordboy23

What does it mean for one set (call it A) to be a subset of another (call it B)? Every element in A must be an element in B. You must show that every element satisfies this requirement, or else it isn't a subset.