How we worked it out
Updated as you change the numbers.
- x = (−b ± √(b² − 4ac)) ÷ 2a.
- Discriminant = (-4)² − 4 × 2 × -6 = 64.
- x = (4 ± √64) ÷ 4.
Method and assumptions
The quadratic formula gives both roots. The discriminant tells you what kind: positive means two real roots, zero one repeated root, negative two complex conjugate roots. The vertex of the parabola is at x = −b ÷ 2a.
Questions
What are the roots of 2x² − 4x − 6 = 0?
x = 3 and x = −1.
Sources
Method and figures checked on . Every worked answer on this page is covered by an automated test. Found a mistake? Tell us.