00:01
So going through these, we can say that a is going to be a subspace.
00:05
That's going to be the set of x1, x2, transpose, an element of r2.
00:14
This is a subspace as well as b is going to be a subspace as well.
00:22
That's the set of all x1, x2 transpose, such that x1 plus x2 is equal.
00:30
To zero.
00:32
This is going to be a line for the origin with slope negative 1.
00:35
It contains 0 -0, so that's yes, and it's closed under addition and scalar multiplication, so therefore, yes.
00:42
But c is not going to be a subspace because this would include vectors where either x1 equals 0 or x2 equals 0, in other words, the union of the axes.
00:53
It does contain 0 -0...