Most curves you meet belong to a family with a shared shape and a few dials (parameters) that stretch, shift or flip it:

• Line — y = a·x + b (slope a, height b)
• Parabola — y = a·x² + b·x + c (a U or ∩)
• Sine wave — y = a·sin(b·x) (amplitude |a|, angular frequency b; ordinary frequency |b|/(2π))