SOLUTION: Find the center, foci, vertices, length of major axis, and length of minor axis of the ellipse 25(x-2)^2 + 4(y+5)^2 = 100. Sketch the graph of the ellipse. Thanks in advance... (^2

Algebra.Com
Question 325483: Find the center, foci, vertices, length of major axis, and length of minor axis of the ellipse 25(x-2)^2 + 4(y+5)^2 = 100. Sketch the graph of the ellipse. Thanks in advance... (^2 means squared)
Answer by Edwin McCravy(20055)   (Show Source): You can put this solution on YOUR website!

The standard forms for ellipses are

 for ellipses like this  where a > b

 for ellipses like this  where a < b



To get 1 on the right, divide through by 



Simplify:



Since the larger number is under the expression in y the ellipse is 
of the form  
and is like this  

, ,  or , , or 

center = (h,k) = (2,-5)

So let's begin by plotting the center (2,-5)

  

Next we draw a vertical line beginning at the center
(2,-5) and going upward  units, which is one-half the
major axis.  This ends in the point (2,0) which is the upper
vertex. 
 





Next we draw a vertical line beginning at the center
(2,-5) and going downward  units, which is one-half the
major axis.  This ends in the point (2,-10) which is the lower
vertex.  That green line is the major axis, and it is 10 units long.
 
 


Next we draw a horizontal line beginning at the center
(2,-5) and going to the right  units, which is one-half the
minor axis. This ends in the point (4,-5) which is the right co-vertex. 
 


Next we draw a horizontal line beginning at the center
(2,-5) and going to the leftt  units, which is one-half the
minor axis. This ends in the point (0,-5) which is the left co-vertex.
The horizontal green line is is the minor axis, and it is 4 units long.
 


Now we can sketch in the ellipse:



Finally we find the foci.  They are the two points on the major axis
w2hich are c units from the center, where c is calculated by







So we add  to the y-coordinate of the center
to find the upper focus, which is the point
(2,), which is about (2,9.6),
marked in red below.


 
And we subtract  from the y-coordinate of the center
to find the lower focus, which is the point
(2,), which is about (2,0.4),
also marked in red below.



Edwin


RELATED QUESTIONS

For the given ellipse, find the principal axis, center, vertices, co-vertices, foci,... (answered by Edwin McCravy)
For the following ellipse: (x + 2)2 + (y + 2)2 = 1 (answered by Boreal)
Can you help me find the center, foci, vertices, length of the major and minor axis of... (answered by lwsshak3)
x^2/25+y^2/16=1 what are its vertices,foci,eccentricty of the ellipse? length of major (answered by ikleyn)
How do I identify the center, co-vertices, foci, length of major axis, length of minor... (answered by lwsshak3)
Length of major axis=4 Length of minor axis=2 Foci on y-axis. Center at the... (answered by Edwin McCravy)
find the answers of the following: ellipse: 4X^2+y^2+8X-4y-92=0 find its... (answered by jsmallt9)
Find the equation of the ellipse with center (–5, –2), horizontal major axis of length 6, (answered by stanbon)
Given the ellipse with equation:(x-5)^2/16+(y=1)^2/25=1 Find the center, the length of... (answered by stanbon)