FUN007 · Functions & graphs · Classes 9–12
Parabola Graph
The graph of y = ax² + bx + c. It opens up when a > 0 and down when a < 0.
Parabola Graph📐 Formula
Vertex x = −b/(2a); roots x = [−b ± √(b² − 4ac)] ÷ 2a
✏️ Worked example
y = x² − 4x + 3: vertex (2, −1); roots x = 1 and 3.
🌍 Where it is used
Projectile paths, fountains and bridge arches.
❓ Quick check
Vertex x-coordinate of y = 2x² − 8x + 1: