Let a, b, c be real and ax2+bx+c=0 has two real roots α and β where α<–1andβ>1, then 1+ca+∣∣ba∣∣
< 0
Since, α<−1andβ>1
∴α+λ=−1 and β=1+μ where λ,μ>0Now,1+ca+∣∣ba∣∣=1+αβ+|α−β|=1+(−1,−λ)(1+μ)+|−1−λ+1+μ|=1−1−μ−λ−λμ+|μ−λ|{−μ−λ−λμ+μ−λ,if μ>λ−μ−λ−λμ+λ−μ,if λ>μ∴1+ca+∣∣ba∣∣=−2λ−λμ or −2μ−λμIn both cases 1+ca+∣∣ba∣∣<0 (∵λ,μ>0)