# Question on Null and Image Space! matrices! wee!

1. Nov 29, 2005

### mr_coffee

Hello everyone!! I'm alittle confused, my professor found the Null space after some students didn't get how to do it, such as myself. Here is the image and problem:
http://img497.imageshack.us/img497/4161/lastscan9es.jpg [Broken]
Thats the row reduced forum of the orginal matrix. The orginal matrix was:
-1 4 1
7 -9 0
10 3 -3
-9 1 2

he added a column of 0's so it wuold make it a square matrix, then he row reduced to get the matrix in the link.
I understand where the Null space of A is:
9/37
7/37
1
0

that makes sense to me, but then he adds in:
d =
0
0
0
1
why is that also a set of vectors in the Null space? d is just all 0's, how can he have a 1 also?

Then i'm lost on what i'm suppose to do to find the image space, you can see my work in the image above. What do i do after i set them equal to r,s,t,u? Thanks!

Last edited by a moderator: May 2, 2017
2. Nov 29, 2005

### mr_coffee

I was going to make a new thread, but its the same question different problem. Did I find the correct image space on this problem?
http://img500.imageshack.us/img500/2195/lastscan7tn.jpg [Broken]
THanks!

Last edited by a moderator: May 2, 2017