Search All of the Math Forum:
Views expressed in these public forums are not endorsed by
NCTM or The Math Forum.


Math Forum
»
Discussions
»
sci.math.*
»
sci.math
Notice: We are no longer accepting new posts, but the forums will continue to be readable.
Topic:
Help with linear System
Replies:
2
Last Post:
Jul 12, 1996 9:13 PM




Help with linear System
Posted:
Jul 7, 1996 3:32 PM


Help!!!!!! I have been given a problem which I have reduced to the following linear system:
z+w=102 x+y=129 z+y=75 w+x=156
Now, I want to solve. But every time I try to use substitution, I don't get anywhere. So, I figured on trying to set it up as a matrix, and solving using Cramer's Rule. But the matrix:
1 0 0 1 0 1 1 0 0 0 1 1 1 1 0 0
Has a determinant of 0, which my math book says results in no or infinant many solutions. So, as I last resourt, I entered it into my HP48's linear system solver. It (for those who aren't farmiliar with the HP48) asks for a coefficient's matrix, a constant matrix, and then spits back the solution in matrix form: [52 104 25 50]. My question is: HOW DID IT ARRIVE AT THIS ANSWER? I would think that it would utilize Cramer's rule and determinants, except that the determinant of the coefficient matrix is zero. Anyone know how the heck the HP48 solved this, or know of another method which I might be able to try to help me arrive at the correct answer? ...Eric Jonas ericj@primenet.com P.S. Could you also please email me any information you discover? My ISP's news server has been experiencing difficulties over the past several days, and I don't want to miss any information which might point me in the right direction.



