Question

If the sum of two of the roots of $x^3+p{x}^2+qx+r=0$ is zero, then pq =

• A. - r
• B. r
• C. 2 r
• D. - 2 r

Answer 1

The correct option is B

r

Given that, α + β = 0

α + β + γ = -p ⇒ γ = -p

Substituting γ = -p in the given equation

⇒ $-p^3+p^3-pq+r=0$ ⇒ pq =r