AlgèbreFacile
Math Learning PlatformSec 4 SN — Quadratic Functions
Intermediate
📚 equations
📖 About this lesson
In-depth study of quadratic functions, vertex and discriminant
Lesson Content
Quadratic Functions
f(x) = ax² + bx + c (a ≠ 0)
Vertex form: f(x) = a(x-h)² + k
h = -b(2a), k = f(h)
Discriminant: Δ = b² - 4ac
- •Δ > 0: 2 real roots
Δ = 0: 1 double root- •Δ < 0: no real roots
Quadratic formula: x = (-b ± √Δ) / (2a)
Practical Examples
1
Example 1
📋 Problem
Trouver le sommet de f(x) = 2x² - 8x + 3
✅ Solution
Sommet : (2, -5)
💡 Explanation
h = -(-8)(2×2) = 2. k = 2(4) - 8(2) + 3 = 8 - 16 + 3 = -5
2
Example 2
📋 Problem
Résoudre x² - 5x + 6 = 0
✅ Solution
x = 2 ou x = 3
💡 Explanation
Δ = 25-24 = 1. x = (5±1)2. x₁=3, x₂=2
Ready to Practice? 💪
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