Can These Vector Sets Span Their Indicated Spaces?

  • Thread starter Thread starter testme
  • Start date Start date
  • Tags Tags
    Set Span Vectors
testme
Messages
68
Reaction score
0

Homework Statement


Determine if the following sets of vectors span the indicated space

a) {[0 -6 -6], [8 -3 5], [-9 7 -2]}, ℝ3.
b) {[2 1 7 -2], [3 5 4 5], [4 -4 -3 -3], [-5 0 6 -4]}, ℝ4.

Homework Equations





The Attempt at a Solution


a) a[0 -6 -6] + b[8 -3 5] + c[-9 7 -2] = [x y z]
x = 8b - 9c
y = -6a -3b + 7c
z = -6a + 5b - 2c

I don't know where to go from here - I'm sure if I can figure that out I'll be able to do b as well.
 
Physics news on Phys.org
Use row reduction.
 
We haven't been taught that yet that's why I'm not sure what he wants us to do..

We've been talking about linear independence, bases, and dimension but I don't know how I can go back and check if it spans the space.
 
Have you been taught determinants? It would be much faster, but row reduction will give you the answer nicely.
 
No, we haven't really been taught how to do anything with matrices, except maybe adding matrices or multiplying matrices by a scalar.
 
testme said:
No, we haven't really been taught how to do anything with matrices, except maybe adding matrices or multiplying matrices by a scalar.

Google row reduction. There's lots of stuff out there and it really only takes 20-30 mins to learn once you've seen a few examples done.

EDIT : Here's a great explanation with an example :
 
Last edited by a moderator:
Hmm, well, that helps, I think I can figure it out from here and I'll ask my professor if there was another method he expected us to know
 
Back
Top