a question on polynomial... (1 Viewer)

shinigami66

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is a root of and does not equal to 2,-6

i showed the first question and second question that
i)
ii)

but im up to the third part of the question that asks me to deduce if is a multiple root, then its multiplicity must be 2...

the answer is that if is a multiple root, then must also be a multiple root...
the question i wanna ask is, why is that???
thank you =]

edit: im guessing its something to do with the polynomial's symmetrical property??? mabe not... hah
 

Timothy.Siu

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its because roots all at a time =1 right?
but u proved that roots cant be +-1
if alpha is a multiple root, then it has to be 2, because it cant be 3 or 4, or then roots all at a time wont =1
and also if alpha is a multiple root then 1/alpha is too since roots all at a time=1
 

shinigami66

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i just aint sure why if alpha is a multiple root, then the reciprocal is also a multiple root...
 

Timothy.Siu

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i just aint sure why if alpha is a multiple root, then the reciprocal is also a multiple root...
ok, u proved that if A is a root, then 1/A is a root right?

then if A is a multiple root, let the other root be B,
product of roots is A^2 x 1/A x B=1
AB=1
B=1/A
 

SparkyZ

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You guys all missed the fact that it's actually a Symmetrical Polynomial. Therefore the roots will be reciprocals of each other.
Which only leaves two pairs of reciprocal roots, therefore the maximum multiple root is only two.
 
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addikaye03

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You guys all missed the fact that it's actually a Symmetrical Polynomial. Therefore the roots will be reciprocals of each other.
Which only leaves two pairs of reciprocal roots, therefore the maximum multiple root is only two.
yep, i saw that aswell.
 

shinigami66

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to GUSSSS - lolx, i used to like animes =p so u might noe where my name came from
to MC - really??? i think it was in one of my skools past paper :S XD
 

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