Conic Sections

Parabola

  • Equation: (y^2=4ax), a real number
  • Focus: ((a,0)), the point
  • Directrix: (x=-a), the vertical with equation

Ellipse

  • Equation: (\frac{x^2}{a^2}+\frac{y^2}{b^2}=1), (a), (b) positive numbers.
  • Foci: ((c,0),(-c,0)), where, (c^2=a^2-b^2)
  • Directrices: (x=\pm\frac{a^2}{c}), the vertical with equations
  • Eccentricity: (e=\frac{c}{a}), (0<e<1)

Hyperbola

  • Equation: (\frac{x^2}{a^2}-\frac{y^2}{b^2}=1), (a), (b) positive numbers.
  • Foci: ((c,0),(-c,0)), where, (c^2=a^2+b^2)
  • Directrices: The vertical lines (x=\pm\frac{a^2}{c})
  • Eccentricity: (e=\frac{c}{a}), (e>1)
  • Asymptotes: (y=\pm\frac{b}{a}x)


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