=[log‌x]e21 =log‌1−log‌e2=0−2 .......(i) =−2 Let α,β and γ are the roots of the equation Ax3+Bx2+Cx+D=0 ∴ x3+Bx2−x+2=0 .......(ii) ∴ α+β+γ=−B ⇒ γ=−B(∵α+β=0 given ) ∴ −B satisfies the Eq. (ii), ∴ (−B)3+B2+B+2=0 ⇒ B=2