If alpha and beeta are the zeroes of the polynomial f(x)=x^2-x-k, such that alpha -beeta=9,find k
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Hope u understood. K=42.
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abhi9112004:
wrong
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f(x)=x²-x-k
on comparing with ax²+bx+c=0
we get a=1,b=-1andc=-k
(alf-bet)²=alf²+bet²-2alf.bet
9²=(alf+bet)²-4alf.bet
81= (-b/a)²-4×c/a
81= 1²-4×-k
81=1+4k
80=4k
k=20.
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