Last updated on Oct 23, 2026

Quadratic Equations (Leaving Cert Mathematics): Flashcards

📚Flashcards

Revision Notes Model Answers Quizzes Flashcards Exam Questions

Using the Quadratic Formula

Practise the cards

14 cards from this deck

Show

Standard form of quadratic equation

$ax^2 + bx + c = 0$

The quadratic formula

$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$

Discriminant in quadratic formula

$b^2 - 4ac$

Meaning: $b^2 - 4ac > 0$

Two different real solutions

Meaning: $b^2 - 4ac = 0$

One repeated real solution

Meaning: $b^2 - 4ac < 0$

No real solutions (complex solutions)

$\pm$ symbol in quadratic formula

Plus or minus; gives two possible solutions

Coefficient $a$ in $ax^2 + bx + c = 0$

Coefficient of $x^2$

Coefficient $b$ in $ax^2 + bx + c = 0$

Coefficient of $x$

Coefficient $c$ in $ax^2 + bx + c = 0$

Constant term

Condition for $a$ in quadratic equation

$a \neq 0$

When to use quadratic formula

When factorisation not easy or need exact decimal answers

First step using quadratic formula

Identify coefficients $a$ , $b$ , $c$ in standard form

Why quadratic formula is universal

Works for any quadratic equation

Explore Leaving Cert Mathematics Revision Notes by Topics