00:01
Hello there.
00:02
So for this exercise let's first consider that there is a basis b for rn and now we need to prove that the vectors b1 b2 up to bk for if they form a linear independent set in rn if i'm only if the vectors vi v2 bk in the basis b form a linear independent set in rn.
00:30
In our n as well.
00:33
Okay, so here we have a double implication and that means that we need to prove from both sides.
00:40
So let's first prove this direction of the statement.
00:47
So we have that the vectors b1, b2 up to vk form a linearly independent set.
01:04
Okay well this is equivalent to say that the sum from i equals to 1 up to k of alpha i b i is equal to 0 if and only if for all the i equals to 1 up to k the alpha i's are equals to 0 okay, that's the meaning of linearly independent.
01:40
That all this coefficient, the only way that this equation is true is if all these alpha -is are equals to zero.
01:49
Okay, so that's the meaning of being linearly independent.
01:56
Okay, so we have this, and now we're going to use the transition matrix.
02:01
So we're going to consider the detransition matrix from the standard basis to the basis b, because let's remember that these vectors are in the standard basis of our n.
02:13
So if we are going to apply some transition matrix, we're going to transform from the standard basis to the basis b...