Question

For the equation 3x² + px + 3 = 0, p > 0, if one of the root is square of the other, then p is equal to

• A. 1/3
• B. 1
• C. 3
• D. 2/3

Answer 1

Answer: (A)

1/3

Answer 2

Let α, α² be the roots of 3x² + px + 3 = 0

Now S = α + α² = - p/3, p = α³ = 1 ⇒ α = 1, ω, ω²;

α + α² = - p/3 ⇒ ω + ω² = -p/3 ⇒ - 1= -p/3 ⇒ p = 3