Ellipse
Chapter Name : Conic Section |
Sub Topic Code : 104_11_11_05_03 |
Topic Name : Ellipse |
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Sub Topic Name : Eccentricity |
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Introduction
• Ellipse is set of points in a plane whose distance from foci adds up to constant. • Eccentricity is the ratio of distance between foci and one of the vertices of an ellipse. • The term eccentricity is used to describe how round or how stretched out an ellipse is.
Pre-Requisites:
• Knowledge of equation of line. • Knowledge of ellipse. • Knowledge of special cases of ellipse.
Activity:
You will observe that different values of eccentricities make different curves.
Real Life Question:
Is eccentricity of earth’s orbit large or small?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Ellipse | Ellipse is set of points in a plane whose distance from foci adds up to constant. |
| Eccentricity | Ratio of distance between foci and one of the vertices of ellipse. |
| Parabola | Set of all points in a plane those are equidistant from a point and a line. |
| Hyperbola | Hyperbola looks like two mirrored parabolas. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Graph paper, Pencil | Draw ellipse on X and Y axis of graph. Find out eccentricity of ellipse and increase the eccentricity of ellipse. |
Real life uses :
Eccentricity is used in Astronomy.
Places to visit :
Look for things in your house which are elliptical in shape?
Practical examples around us
| Examples | Explainations |
|---|---|
| Eccentricity of planets. | Scientists use the term eccentricity to describe how round or stretched out planet’s orbit is since orbits of planets in solar system is elliptical with sun as focus. |
What you learn in Theory:
With different values of eccentricities we can form different curves. When eccentricity is zero we get circle and with infinite eccentricity we get line.
What you learn in Practice:
Eccentricity is used to determine planet’s orbit.