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sahilwasan said – Tue, 10 Mar 2009 19:07:35 -0000 ( Edit Link )

If the quadratic equation (a^2+b2)x^{2+2b(a+c)x+(b}2+c^2)=0 has equal roots, then (A) a, b and c are in A.P. (B) a, b and c are in G.P. (C) a, c and b are in A.P. (D) a, c and b are in G.P.

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nipunmad said – Wed, 11 Mar 2009 18:54:38 -0000 ( Flag Edit Mark / Unmark Best Link )

the ques is not clear please clarify it
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iwa said – Sat, 14 Mar 2009 12:45:55 -0000 ( Flag Edit Mark / Unmark Best Link )

pls just clarify the que a bit more?
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Sureshbala said – Thu, 19 Mar 2009 14:45:36 -0000 ( Flag Edit Mark / Unmark Best Link )

Since the roots are equal the discriminant is 0 i.e $\sqrt{b^2-4ac}=0$
$\Rightarrow b^2 = 4ac$
$\Rightarrow 4b^2 (a+c)^2$
$\Rightarrow b^2 a^2 + b^2 c^2 + b^2 2ac$
$\Rightarrow b^2 2ac = a^2 c^2 + b^4$
The above equation will hold if
Hence a,b, and c are in G.P
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The_Ahmad said – Sat, 21 Mar 2009 14:23:15 -0000 ( Flag Edit Mark / Unmark Best Link )

Nice, Sureshbala, the question wasn’t that clear at first.
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man_raj said – Thu, 16 Apr 2009 01:05:06 -0000 ( Flag Edit Mark / Unmark Best Link )

wat Sureshbala did is absolutely right.There is no confusion at all
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