Page 67 - DMTH201_Basic Mathematics-1
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Basic Mathematics – I
Notes
3 3
A B ...(4)
4 14
From (3) and (4) (A ) B A B .
2 3 1
Example: Find the matrices A and B given that 2A B and
1 4 0
4 6 1
3A 2B
2 3 5
Solution:
2 3 1
2A B ...(1)
1 4 0
4 6 1
3A 2B ...(2)
2 3 5
Multiply (1) by (2)
4 6 2
(1) 2 4A 2B
2 8 0
4 6 1
(2) 3A 2B
2 3 5
0 0 1
Subtracting, we get A
0 5 5
Substituting this in (1), we get
0 0 1 2 3 1
2 B
0 5 5 1 4 0
2 3 1 0 0 2
B
1 4 0 0 10 10
2 0 3 0 1 2 2 3 1
1 0 4 10 0 10 1 6 10
0 0 1 2 3 1
A , B
0 5 5 1 6 10
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