If 2 and –3 are the roots of a quadratic equation, then the quadratic equation is:
- AOption (a)
x2 + x + 6 = 0
- BOption (b)
x2 – x – 6 = 0
- COption (c)
x2 + x – 6 = 0
- DOption (d)
x2 – x + 6 = 0
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Correct answer
x2 + x – 6 = 0
Why this answer is correct
Shortcut Trick For any roots α and β, the quadratic equation is x2 − (Sum)x + (Product) = 0. Sum of roots = 2 + (−3) = −1 Product of roots = 2 × (−3) = −6 Equation ⇒ x2 − (−1)x + (−6) = x2 + x − 6 = 0. ∴ The correct answer is x2 + x − 6 = 0. Alternate Method Given: The roots of the required quadratic equation are 2 and −3. Formula Used: If α and β are the roots, then the equation is x2 − (α + β)x + αβ = 0 Calculations: ⇒ Let α = 2 and β = −3 ⇒ Sum of roots (α + β) = 2 + (−3) = −1 ⇒ Product of roots (αβ) = 2 × (−3) = −6 ⇒ Substituting these values into the formula: ⇒ x2 − (−1)x + (−6) = 0 ⇒ x2 + x − 6 = 0 ∴ The correct answer is x2 + x − 6 = 0. Additional Information General Form of Quadratic Equation A quadratic equation is typically expressed as ax2 + bx + c = 0, where a, b, and c are constants and a ≠ 0. Nature of Roots The discriminant D = b2 − 4ac determines the nature: D > 0 (real and distinct), D = 0 (real and equal), and D < 0 (imaginary). Vieta's Formulas For the equation ax2 + bx + c = 0, the sum of roots is −b/a and the product of roots is c/a.



