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Hello.
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So here we're given a given matrix a, where a matrix a is b3, b2, where we're told b is not equal to zero.
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So we take a matrix a and then we concatenate it with the two -by -two identity matrix on the other side of this vertical line.
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And now we're going to perform just elementary row operations to take to basically put the identity on the left -hand side of this line.
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And then what we end up with on the right -hand side is going to be our inverse matrix.
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So we want to have a 1 in our first spot.
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Here we now have a b.
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So therefore, we just multiply by 1 over b.
00:38
And then we want to take, well, a 0 beneath it.
00:41
So then we just take row 1 minus row 2.
00:44
So our operations are going to be row 1 here becomes row, well, 1 over b times row 1.
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So that's row 1 over b, multiple by 1 over b, and then we take our 2 becomes, well, row 1 minus row 2.
01:05
Okay, and if we do that, then we end up with, well, 1, and then 3 over b, and then 0, 1.
01:17
Okay, so we got our 1 in our first spot and a 0 beneath it, okay, which is what we wanted.
01:21
And then on the other side of that vertical line, we end up with 1 over b and then 0 and then 1 and then negative 1...