Question 23284:  Please help! 
Like all planets Jupiter has an elliptical orbit, with the centre of the sun located at a focus. Write an equation of the ellipse that models Jupiter's orbit around the sun. Assume that the centre of the sun in on x-axis. 
          
------------------jupiter
 
__740_____sun___810______   --------> assuming this is a ellipse and Jupiter    is 
 
 
                                          around the orbit of the sun. 
 Answer by venugopalramana(3286)      (Show Source): 
You can  put this solution on YOUR website! standard eqn. of an ellipse with foci on x axis,centre as origin  and directrices parallel to y axis is  
(X^2/A^2)+(Y^2/B^2)=1,where A and B are semi major/minor axes 
foci are given by (A*E,0),(-A*E,0) 
eccentricity =E =[(A^2-B^2)/A^2]^0.5 
we are given the sun is at one focus and the 2 numbers you have given as 740 and 810 are  NOT ELABORATED AS TO WHAT THESE NUMBERS ARE. 
 
I back calculated the major / minor axes as per the answer given by you and came out		 
with following interpretation of the numbers given by you.		 
740 is the minimum distance of jupiter from sun	 
810 is the maximum distance of jupiter from sun	 
so total distance =major axis ,since sun is at one of the foci and is on x axis or major axis		 
major axis =2*A=740+810=1550..or A=1550/2= 775		 
as given above foci are given by (A*E,0) and (-A*E,0),with centre taken as origin.		 
since sun is at focus and its coordinate is  (775-740,0) and (775-810,0) or (35,0),(-35,0) we have		 
A*E=35..that is.... 775*E=35...or....E=35/775=7/155 		 
further we have E=[(A^2-B^2)/A^2]^0.5		 
so  B=[A^2-(E^2)(A^2)]^0.5 =A*(1-E^2)^0.5=774.2093		 
hence eqn. Of ellipse is 		 
(X^2/775^2)+(Y^2/774.2093^2)=1		 
(X^2/600625)+(Y^2/599400)=1		 
 
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