Question 1181020:  Dear Sir/Ma'am
 
Please Help me solve this problem.
 
Find the equation if the Ellipse with center at (2,3), Vertices at (2,9) and (2,-3) and Eccentricity of 2/3/ Identify the parts of the Ellipse and sketch the graph.
 
Parts of the Ellipse 
1. Center 
2. Foci 
3. Vertices V1, V2 
4. Co Vertices B1, B2 
5. Endpoints of Latus Rectum E1, E2, E3, E4 
6. Directrices 
7. Eccentricity 
8. Length of LR 
9. Length of Major Axis 
10. Length of Minor Axis
 
Thank you and GOD Bless
 
Sincerely Yours,
 
Lorna
 
 
 Answer by MathLover1(20850)      (Show Source): 
You can  put this solution on YOUR website! equation:
 
 
 
given:
 
center at ( , )=>  and  
 
Vertices at ( , ) and ( , ) 
as you can see major axis is parallel to y-axis, so it is  ,the ellipse is vertical 
 
and distance between vertices is   
=> 
 
so far your equation is:
 
 
 
given ccentricity of   
The eccentricity (e) of an ellipse is the ratio of the distance from the center to the foci (c) and the distance from the center to the vertices (b).
 
  
  
  
 
 
now find minor axis   
  
 
 
 
 
 
semimajor axis length :   
semiminor axis length:  ≈  
major axis length :   
minor axis length:  
 
foci: 
( ,   ), ( ,   ) 
=>( ,   ), ( ,   ) 
=>( ,   ), ( ,   )
 
 
foci:  
( ,  ) , ( ,  ) 
( ,  ) , ( ,  ) 
( ,  ) , ( ,  )
 
covertices: 
( ,  ) ,( ,  )  
( ,  ), ( ,  ) 
≈( ,  ) , ( ,  )
 
 
eccentricity:  
 
directrices: since you have vertical ellipse, directrices are     from each y coordinate of the vertices 
  
  
First directrix:  
 
Second directrix:  
 
Endpoints of Latus Rectum 
The chord of the ellipse through its one focus and perpendicular to the major axis (or parallel to the directrix) is called the latus rectum of the ellipse.
 
since foci is at: ( ,  ) , ( ,  )
 
first latus rectum:   
substitute in ellipse formula and you get 
  or  
 
two Endpoints of Latus Rectum are 
E1= ,  and  E1= , 
 
second latus rectum:   
  same as above
 
E3= ,  and  E4= , 
 
  
 
 
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