Topic: Parametric, Polar, and Conic Curves
Subtopic: Polar Equations of Conic Sections
Overview
Start by reviewing conic sections from a pre-calculus course. See Lesson Notes - College Algebra: Introduction to Conics | Parabolas | Ellipses | Hyperbolas | General & Degenerate Conics but ignore the "text notes". Work conics that are centered at the origin as well as those translated away from the origin.
Our main goal in this lesson is to concentrate performing calculus on the conic sections. Many calculus operations are simplified by converting the equations of the conics from rectangular form to polar form. This transformation is accomplished through an ingenious formula. We can then apply calculus to the polar form to find the area inside a bounded conic, the arc length of the conic, etc. Study conics that have horizontal or vertical axes as well as those that have a rotated axis.
Objectives
By the end of this topic you should know and be prepared to be tested on:
- 10.3.1 Understand the rectangular equations and graphs of conic sections including those with centers translated away from the origin
- 10.3.2 Use the formula r = (e·d)/(1±cosθ) or r = (e·d)/(1±sinθ) to convert equations of conics from rectangular to polar form
- 10.3.3 Identify a conic from its polar form
- 10.3.4 Understand the eccentricity of the conic sections and identify a conic given its eccentricity
- 10.3.5 Graph a polar equation of a conic manually and electronically
- 10.3.6 Find the polar equation of a conic given its graph or information about its graph
- 10.3.7 Understand some applications of conics in polar form including Kepler's Laws
Terminology
Define: focal point, major and minor axes, directrix, pole, eccentricity, Kepler and his laws
Supplemental Resources (recommended)
Explore the connection between eccentricity and conics via the java applet at www.mathwords.com/multimedia/Conics%20defined%20by%20eccentricity.htm.
Supplemental Resources (optional)
These are both quite good reads. The first reviews concepts from Pre-Caluclus and the second covers Calculus concepts.
Lesson: Conic Sections, Dale Hoffman's Contemporary Calculus
Lesson: Properties of the Conic Sections, Dale Hoffman's Contemporary Calculus