It is given that the inverse of
(m -m-2)
n-2 4 is (4m 3n )
( 1 n^2)
Find m and n. I multiply 1/determinant with the terms in bracket after swopping the 4 terms to get the inverse so as to equate it to (4m 3n ), however the terms I got is simply too huge to be solved.
( 1 n^2)
Please help. Thank you.
what is the model answer?
btw i get m = 1, 0.7912, -3.7912
Keep it easy.
(matrix)(inverse matrix) = (identity matrix)
Simply find the product of the 2 matrixes given to u and equate to
(1 0)
(0 1)
m = 1 and n = 1
Originally posted by Mikethm:Keep it easy.
(matrix)(inverse matrix) = (identity matrix)
Simply find the product of the 2 matrixes given to u and equate to
(1 0)
(0 1)
m = 1 and n = 1
me dun c de link...
any square matrix multiply by its inverse will give a matrix of diagonal = 1 and rest being 0
Originally posted by tr@nsp0rt_F3V3R:me dun c de link...
Let's call the 1st matrix A and the 2nd matrix B.
Since B is the inverse of A
than AB = I ( where I is the identity matrix)
This should be quite clear unless you have not been taught that a matrix multiplied by its inverse is the identity matrix.
Sadly, the syllabus between A and E Maths is a little disjointed in the sense that the above is not specifically in syllabus. However, the requirement in A Maths is such that you do not really understand the concept behind how to solve simultaneous equations by matrix unless you understand the above... you do not really know the logic behind the matrix solutions.
However both the PenPac and ShingLee textbooks bothered to explain it, so you should refer to any of these for an explanation of the concepts and relationship between a matrix, its inverse and the identity matrix. :)
Originally posted by Mikethm:Keep it easy.
(matrix)(inverse matrix) = (identity matrix)
Simply find the product of the 2 matrixes given to u and equate to
(1 0)
(0 1)
m = 1 and n = 1
May I know why you equate it to ( 1 0 )?
( 0 1)
Originally posted by bonkysleuth:
May I know why you equate it to ( 1 0 )?( 0 1)
If you have the ShingLee textbook, read chapter 8.2 (page 216 & 217).
If you have the PenPac textbook, read Example 6 on page 6/7 followed by the later part of page 7.
Examples on the internet are a bit too complex for O level.
Originally posted by Mikethm:
If you have the ShingLee textbook, read chapter 8.2 (page 216 & 217).If you have the PenPac textbook, read Example 6 on page 6/7 followed by the later part of page 7.
Examples on the internet are a bit too complex for O level.
I got -3/4 and 1 for m and =1/7 and 1 for n. Why do we have to reject the negative values?
Good. You got to the possible values. Now your question say "Find m and n", this imply that only one solution is acceptable. Now don't be lazy and test which pair is the correct one. :PPPPPP