Algebraic Curves

Discover what algebraic curves are: the zero sets of polynomial equations. Explore lines, conics, and beautiful higher-degree curves.

What is an Algebraic Curve?

An algebraic curve is the set of all points (x, y) that satisfy a polynomial equation f(x, y) = 0. This simple definition leads to an incredibly rich theory connecting algebra and geometry.

From straight lines to exotic curves with loops and cusps, every algebraic curve tells a story about its defining polynomial. The degree of the polynomial determines the curve's fundamental properties.

Demo 1: Build Your Own Curve

Adjust the coefficients of a general degree-2 polynomial and watch the curve change in real-time. Try the presets to see familiar shapes emerge.

x² +y² -1 = 0

Adjust the sliders to change coefficients. The curve shows all points (x, y) where the polynomial equals zero.

Demo 2: Gallery of Curves

Explore a collection of famous algebraic curves. Click on each to see its equation and discover its unique properties.

Degree 2
Degree 3
Famous

Unit Circle

x^2 + y^2 = 1

The fundamental circle with radius 1 centered at the origin

Click on different curves to explore their shapes. Notice how higher-degree curves have more complex features.

Demo 3: How Degree Shapes Curves

The degree of a curve is the highest total power of x and y in any term. Higher degree means more complex possible shapes.

1 (linear)2 (quadratic)3 (cubic)4 (quartic)5 (quintic)

Circle (conic)

x² + y² = 4

What degree tells us:

  • Degree 1: Always a straight line
  • Degree 2: Conics (circle, ellipse, hyperbola, parabola)
  • Degree 3: Can have loops, cusps, or inflection points
  • Degree 4+: Increasingly complex shapes possible

Curves: The Foundation

You've learned the essential concepts of algebraic curves:

  • Definition: A curve is the zero set of a polynomial f(x, y) = 0
  • Degree: The highest total power determines the curve's complexity
  • Coefficients: Small changes can dramatically reshape the curve
  • Classification: Degree 1 = lines, Degree 2 = conics, Degree 3 = cubics

Next: We'll dive deep into degree-2 curves (conics) and discover why circles, ellipses, parabolas, and hyperbolas are all related — they're all slices of a cone!