00:01
Okay, so first of all let's compute the inverse of the matrix 2 1 0 7.
00:09
Okay, so what is the inverse of this matrix here? well, obviously we are gonna have a matrix of the form 1 half, another number here a, 0 and 1 over 7, so we just need to determine a.
00:31
Well, how can we do this? this is pretty easy, we just need to keep in mind that 1 half a 0 1 over 7 multiplied by 2 1 0 7 must be equal to the identity matrix 1 0 0 1.
00:50
Okay, now this product here is equal to 1, the first coordinate, the second entry is gonna be 1 half plus 7 a, perfect, and well this is enough, we don't need these two entries because we get the question this one equal to 0, perfect.
01:16
So what we get? well, we get a equal to negative 1 over 14, perfect.
01:25
Okay, we have found the inverse, this one is negative 1 over 14, perfect.
01:36
Okay, now we can find the matrix associated to our linear transformation.
01:44
Well, this is pretty easy, we just need to compute the images of t on the basis, so we are gonna compute t of 1 0 0 0 and then the other ones.
01:58
Well, this one is equal to 2 1 0 7 multiplied by 1 0 0 0, perfect, multiplied by 1 half, okay, this one was 1 half negative 1 over 14, perfect, negative 1 over 14, 0 1 over 7.
02:25
Okay, now this product here is equal to 2 0, okay, 2 0 0 0, okay, multiplied by this guy here, 1 half negative 1 over 14, 0 1 over 7, perfect, and what do we get? well, we get 1 0 0 0, perfect.
02:55
Okay, now let's compute t of 0 1 0 0, okay, so we're gonna use again this expression here, this matrix multiplied by this one, multiplied by this one, okay, perfect.
03:22
So, here we have 2 1 0 7 multiplied by 0 1 0 0, multiplied by 1 half negative 1 over 14, 0 and 1 over 7...