document.write( "Question 426511: 1. Find the coordinates of the foci of the ellipse represented by x2 + 25y2 – 6x – 100y + 84 = 0. \n" ); document.write( "
Algebra.Com's Answer #297041 by lwsshak3(11628)\"\" \"About 
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Find the coordinates of the foci of the ellipse represented by
\n" ); document.write( "x2 + 25y2 – 6x – 100y + 84 = 0.
\n" ); document.write( "..
\n" ); document.write( "Standard form for ellipse with horizontal major axis:
\n" ); document.write( "(x-h)^2/a^2+(y-k)^2/b^2=1,(a>b), with (h,k)=(x,y) coordinates of center.
\n" ); document.write( "x2+25y2-6x-100y+84=0
\n" ); document.write( "completing the squares
\n" ); document.write( "(x^2-6x+9)+25(y^2-4y+4)=-84+9+100=25
\n" ); document.write( "(x-3)^2/25+(y-2)^2/1=1
\n" ); document.write( "This is an ellipse with a horizontal major axis and center at (3,2)
\n" ); document.write( "a^2=25
\n" ); document.write( "a=5
\n" ); document.write( "length of major axis=2a=10
\n" ); document.write( "b^2=1
\n" ); document.write( "b=1
\n" ); document.write( "length of minor axis=2b=2
\n" ); document.write( "c^2=a^2-b^2=25-1=24
\n" ); document.write( "c=sqrt(24)=4.9
\n" ); document.write( "Foci on the major axis=3+-4.9
\n" ); document.write( "ans:
\n" ); document.write( "Coordinates of foci:(3,-1.9) and (3,7.9)
\n" ); document.write( "See graph of ellipse below:\r
\n" ); document.write( "\n" ); document.write( "..
\n" ); document.write( "y=2+((25-(x-3)^2)/25)^.5
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