Calculus Volume 2 · free preview

Conic Sections

Parabolas, ellipses, and hyperbolas are the conic sections, defined by eccentricity and focus-directrix geometry, unified by the polar equation r equals ed over 1 plus e cos theta with the eccentricity discriminating the type.

1. The conic family

The conic family

2. Reflective and orbital properties

Reflective and orbital properties

3. The polar conic equation

The polar conic equation

4. Graphing and standard forms

Graphing and standard forms

5. Eccentricity discrimination

The eccentricity e discriminates the conic families. Which value gives a parabola?

6. Ellipse focus relation

For the ellipse x^2/a^2 + y^2/b^2 = 1 with a greater than b, the foci satisfy which relation?

7. Parabola reflection property

A parabolic reflector works by which geometric property?

8. Polar conic equation

The polar equation r = ed/(1 + e cos theta) with e = 1/2 describes which conic?

9. Kepler first law

Kepler's first law states that planets move in which conic with the sun at a focus?

10. Perihelion distance

For the ellipse r = ed/(1 + e cos theta), the perihelion occurs at theta = pi. As an expression, what is r there? Answer like ed/(1 + e).

11. Hyperbola asymptote condition

For e greater than 1 the denominator 1 + e cos theta vanishes at cos theta = -1/e, giving the hyperbola's what? Answer with one word.

12. Discriminant of conic

The general quadratic's discriminant B^2 - 4AC classifies conics. For the ellipse it is which sign? Answer with one word.

13. Discriminant sign summary

The conic discriminant B^2 - 4AC is zero for the parabola, positive for the hyperbola, and which sign for the ellipse? Answer with one word.

14. Directrix location

In the polar conic r = ed/(1 + e cos theta), the directrix sits at x equals which value? Answer with a single letter.

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