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Algebra

Q1. The roots alpha and betaof quadratioc equation pxsquare+qx+r are real and of opposite sign .
the roots of alpha(x-beta)square+beta(x-alpha)square=0are
a) positive
b) neagative
c) real and of opposite sign
d) imaginary

Profile image of anurag singhal
16 Years agoGrade
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1 Answer

Profile image of askiitian.expert- chandra sekhar
16 Years ago

α(x-β)2+β(x-α)2=0    ---(1)

Given α and β are real and of opposite sign

Therefore αβ= -ve

From equation 1

α(x2+β2-2xβ) + β(x2+α2-2αx)=0

(α+β)x2-4αβx+αβ(α+β)=0

product of the roots = αβ(α+β)/(α+β)= αβ = -ve

discriminant Δ=16 α2β2-4 αβ( α+β)2 

as 16 α2β2 and ( α+β)2 are positive and αβ is negative, Δ  is positive

so the roots of the equation are real and opposite in sign.

Ans: c