Mathematical Curves

4. Cardioid

Cartesian Equation of Cardioid is

(x2 + y2 ⎼ 2ax)2 = 4a2(x2 + y2)

Polar Equation of Cardioid is

r = 2a(1 + cosθ)

Parametric Equations are

  • x(t) = a[2 cos t ⎼ cos(2t)]
  • y(t) = a[2 sin t ⎼ sin(2t)]

Notable Facts:

  • (a) There are exactly three parallel tangents at any given point on the cardioid.
  • (b) The tangents at the ends of any chord through the cusp point are at right angles.
  • (c) Trace a point on the circle rolling around another circle of equal radius.

Parabola.

Circle.

Ellipse.

Hyperbola.

1. Astroid

Bicorn

Cardioid

Cartesian Oval

Cassinian Ovals

Catenary

Cayley’s Sextic

Circle

Cissoid of Diocles

Cochleoid

Conchoid

Conchoid of de Sluze

Cycloid

Devil’s Curve

Double Folium

Durer’s Shell Curves

Figure Eight Curve

Ellipse

Epicycloid

Epitrochoid

Equiangular Spiral

Fermat’s Spiral

Folium

Folium of Descartes

Freeth’s Nephroid

Frequency Curve

Hyperbola

Hyperbolic Spiral

Hypocycloid

Hypotrochoid

Involute of a Circle

Kampyle of Eudoxus

Kappa Curve

Lame Curves

Lemniscate of Bernoulli

Limacon of Pascal

Lissajous Curves

Lituus

Neile’s Semi-cubical Parabola

Nephroid

Newton’s Diverging Parabolas

Parabola

Pearls of Sluze

Pear-shaped Quartic

Plateau Curves

Pursuit Curve

Quadratrix of Hippias

Rhodonea Curves

Right Strophoid

Serpentine

Sinusoidal Spirals

Spiral of Archimedes

Spiric Sections

Straight Line

Talbot’s Curve

Tractrix

Tricuspoid

Trident of Newton

Trifolium

Trisectrix of Maclaurin

Tschirnhaus’s Cubic

Watt’s Curve Witch of Agnesi