Conic Sections - Ellipse Help
Favorites|Homepage
Subscriptions | sitemap
HOME > > Conic Sections - Ellipse Help

Conic Sections - Ellipse Help

[From: ] [author: ] [Date: 12-05-23] [Hit: ]
Whats the center (9,-2), the foci, the major and minor axises, and the vertices of this ellipse?Thanks again!......
Hey, I'm still kind of confused as to how to do this for this type of ellipse. If I see it done, than I'll probably be able to understand it better, thanks!

(Standard) Equation: [(x-9)^2/25] + [(y+2)^2/100] = 1

What's the center (9,-2), the foci, the major and minor axises, and the vertices of this ellipse?

Thanks again!

-
[(x - 9)² / 25] + [(y + 2)² / 100] = 1

Center (9, - 2)

Since the larger denominator is on the y side of the equation, the major axis will be parallel to the y axis ('a' is always the larger value), so

a² = 100
b² = 25

a = √(a²)
a = √100
a = ± 10

b = √(b²)
b = √25
b = ± 5

y-axis vertices will be 'a' units above and below the center, so

y = - 2 + 10
y = 8

and

y = - 2 - 10
y = - 12

y vertices (9, 8) & (9, - 12)
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

x vertices will be 'b' units to the left and right of center, so

x = 9 + 5
x = 14

and

x = 9 - 5
x = 4

x vertices (14, - 2) & (4, - 2)
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯

The foci are 'c' units above and below center, and

        ______
c = √ a² - b²
        _______
c = √100 - 25
        ___
c = √ 75

c = ± 8.66

Focus (9 , k ± 8.66), so

Focus (9, - 2 + 8.66)
Focus (9, 6.66)

and

Focus (9, - 2 - 8.66)
Focus (9, - 10.66)

Focii (9, 6.66) & (9, - 10.66)
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
 
1
keywords: Help,Sections,Conic,Ellipse,Conic Sections - Ellipse Help
New
Hot
© 2008-2010 http://www.science-mathematics.com . Program by zplan cms. Theme by wukong .