00:01
Now over here in this question, we've been given two matrices.
00:04
One is matrix a represented to us as 1, 2, 3 and 4.
00:09
These are the elements of matrix a.
00:12
There is another matrix also, that is b, and the matrix is given to us as 1 upon 2 types minus 4, 2, 3 and minus 1 over here.
00:27
So now we simply have to prove that this matrix b is the inverse of matrix a.
00:34
So for that, to prove that b is the inverse of matrix a, what we need to prove is, we will prove that ab is equal to i, that is the identity matrix and this is equal to b.
00:47
So if you are able to prove this thing, only then you'll be able to conclude that yeah, b is the inverse of matrix.
00:56
So we'll start by just finding out ab and then we'll want to eventually move on to b.
01:04
So let's start that.
01:07
Now, if you just look at matrix b over here, what you'll find is there's a scalar quantity 1 upon 2.
01:14
So in such cases, what we can do is we will just multiply the scalar quantity or this value with each and every element of matrix b.
01:24
So what you'll get is minus 2, 1, then 3 upon 2 and minus 1 upon 2.
01:32
So this is the you can say modified b matrix...