00:01
Hello student in this question we are given a determinant.
00:04
So first off write the determinant.
00:07
In the first question we have j square 1 plus j 5 2 1 minus j s 2 the power 4 j minus 3 0.
00:29
So we have to find its determinant which is equal to j square.
00:35
I'm expanding.
00:36
It using the first column this one j square into one sorry zero it is zero minus three j to the power four minus two into zero plus fifteen plus j to minus j four one plus j four one plus j four minus 5 which is equal to minus 3 j to be part 6 minus 30 plus j into minus j 4 minus j 5 minus 5 which is equal to minus 4 j 6 minus j 5 plus 35 all right in the second question we have to find the value of p, q and r.
01:42
When we are given a set of equations, we can write the set of equations as, in the matrix form, we can write it as 1 .3, 3 .7 and 1 minus 2, 4 .8, 3 .8, 1 minus 7, and 12 into pqr equal to 7 .7.
02:13
So here are a is equal to 1 .31 minus 2, 4 .8, 3 .8, 1 minus 7, 12.
02:44
And that x is equal to pqr and b equal to b equal to 730 and b equal to 730.
02:55
So we can write the given set of equations as a x is equal to b and we know how do we find the solution to such kind of system is given by x is equal to a inverse b.
03:13
So we need to find a inverse first.
03:18
For finding a inverse let us write adjoint of a at joint of a is equal to 57 .6 45 .1, 145 .4, 27 .8, 14 .6, minus 6 .94.
03:41
9 .2, 12 .8, 13 .64.
03:49
So, and also, we want modulus of a.
03:54
A modulus is equal to, i'm expanding it through the, using the first road cell.
04:04
Into 4 .8 into 12 plus 7 into 3 .8 plus 2 into 3 .7 into 12 plus 7 plus 3 .7 into 3 .8 minus 4 .8.
04:27
Alright.
04:30
So upon calculating this, we get modulus of a is equal to 4 .30.
04:41
0184 therefore we can get the a inverse is equal to 1 upon modulus of a into a joint of a which is equal to 1 upon 431 .184 into 57 .6 45 .1 45 .4 145 .4 minus 6 .94, 9 .2, 12 .8, 13 .64, which is equal to, on dividing the individual term by 431 .184, we get 0 .134, 0 .105, 0 .337, 0 .337, 0 .0367, 0 .06.
05:43
0 .0 .0 .0 .337.
05:45
0.
05:45
0 .0 .0 .6...