20 carefully selected problems — from foundation to trap questions. Master the concepts that appear most on test day.
🧠 VERTEX: (−b/2a, f(−b/2a))
✂️ ROOTS: x = −b ± √(b²−4ac) / 2a
📦 VERTEX FORM: y = a(x−h)² + k
🎯 PRODUCT: r₁·r₂ = c/a
➕ SUM: r₁+r₂ = −b/a