Unit 5 · 4 lessons

Quadratic Equations

Solve quadratic equations by factoring, with the quadratic formula and by graphing, use the discriminant to tell whether there are two, one or no real roots, and answer real questions about heights, times, areas and revenue.

45 practice questions
30 flashcards
1 interactive lesson

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Lessons

1Solving Quadratic Equations by FactoringRearrange a quadratic equation so one side is zero, factor it, and use the zero product property to find every root. The roots of $a x^{2} + b x + c = 0$ are the $x$ -intercepts of the parabola $y = a x^{2} + b x + c$ .11 questions
2The Quadratic FormulaFollow how completing the square on $a x^{2} + b x + c = 0$ produces the quadratic formula, then use the formula to solve any quadratic equation, giving roots in exact form or rounded, and check them with a graph.11 questions
3Real and Non-Real RootsUse the discriminant $b^{2} - 4 a c$ to tell, before solving, whether a quadratic equation has two real roots, one real root or no real roots, and connect each case to how the parabola meets the $x$ -axis.Interactive11 questions
4Solving Problems with QuadraticsAnswer real questions with quadratic relations: the maximum height of a thrown object, when it lands, how long it stays above a given height, and the dimensions or price that give the greatest area or revenue.12 questions