document.write( "Question 852005: How do I write the standard equation of an ellipse with foci (4,2) and (-2,2) and eccentricity c/a=1/3.? Explain your solution completely \n" ); document.write( "
Algebra.Com's Answer #513070 by lwsshak3(11628)\"\" \"About 
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How do I write the standard equation of an ellipse with foci (4,2) and (-2,2) and eccentricity c/a=1/3.?
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\n" ); document.write( "Ellipse has a horizontal major axis.
\n" ); document.write( "Its standard form of equation: \"%28x-h%29%5E2%2Fa%5E2%2B%28y-k%29%5E2%2Fb%5E2=1\", a>b, (h.k)=center
\n" ); document.write( "x-coordinate of center=1 (midpoint between 4 and-2 on the major axis)
\n" ); document.write( "y-coordinate of center=2
\n" ); document.write( "center: (1,2)
\n" ); document.write( "c=3 (distance from center to foci on the major axis)
\n" ); document.write( "c^2=9
\n" ); document.write( "eccentricity=c/a=1/3
\n" ); document.write( "a=3c=9
\n" ); document.write( "a^2=81
\n" ); document.write( "c^2=a^2-b^2
\n" ); document.write( "b^2=a^2-c^2=81-9=72
\n" ); document.write( "Equation of given ellipse:
\n" ); document.write( "\"%28x-1%29%5E2%2F81%2B%28y-2%29%5E2%2F72=1\" \n" ); document.write( "
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