39
Dr.House
·2009-10-20 05:33:30
is it all that diffiult that it deserves not even a single try in 3 hours??
1
Arshad ~Died~
·2009-10-20 18:28:27
vandermonde matrixor vandermonde polynomial
http://en.wikipedia.org/wiki/Vandermonde_matrix
62
Lokesh Verma
·2009-11-16 04:47:33
This one has been unattended since eternity..
hint: substitute a1=a2
(what can you say?)
39
Dr.House
·2009-11-16 06:30:22
we can say that then 1st 2 rows are equal and hence the determinant becomes zero..
so (a1-a2) is a root of the determinant...
so on proceeding...
we find (a2-a3) is a root , (a3-a4) is a root,........................ (am-1-am) is a root...
so determinant can be written as
(a1-a2)(a2-a3)..................................(am-1-am)
62
Lokesh Verma
·2009-11-16 06:34:44
this much is correct bhargav.. but then why will only these terms be there and no other term?
1
Philip Calvert
·2009-11-16 07:10:16
why can't
(a1-a3)(a1-a4)..(a1-am) (and similar others) be the roots too ??
62
Lokesh Verma
·2009-11-16 07:16:26
they will all be philip..
so the determinant will be?
39
Dr.House
·2009-11-17 04:24:11
ok , so considering all such possiblities,
the determinant can be written as
\prod{(a_{i}-a_{j})}\; where\; 1\leq i<j\leq n