Quadratic Equations Flashcards

Grade 9 · Math · Flashcards

Essential terms and formulas for solving quadratic equations in Grade 9 Math.

Flashcards

Quadratic equation: An equation of the form ax² + bx + c = 0 where a ≠ 0
Standard form: ax² + bx + c = 0
Parabola: The U-shaped graph of a quadratic; opens up if a > 0, down if a < 0
Roots / zeros: The x-values where the quadratic equals zero; where the parabola meets the x-axis
Zero Product Property: If ab = 0, then a = 0 or b = 0
Quadratic formula: x = (−b ± √(b²−4ac)) / 2a
Discriminant: b² − 4ac; tells you how many real solutions exist
Positive discriminant: Two distinct real solutions
Zero discriminant: One repeated real solution (the vertex touches the x-axis)
Negative discriminant: No real solutions (parabola does not cross the x-axis)
Factoring method: Rewrite quadratic as a product of binomials, then use Zero Product Property
Vertex of a parabola: The highest or lowest point of the parabola; at x = −b/2a