document.write( "Question 861160: find the center (h,v) of the ellipse. show work
\n" ); document.write( "Center:(-3,0)
\n" ); document.write( "vertex1:(-3,5)
\n" ); document.write( "vertex2:(-3,-5)
\n" ); document.write( "focus1:(-3,4)
\n" ); document.write( "focus2:(-3,-4)
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Algebra.Com's Answer #518938 by KMST(5328)\"\" \"About 
You can put this solution on YOUR website!
I see the answer to the question: Center:(-3,0) .
\n" ); document.write( "I also see information that would allow to find the center, and the equation of the ellipse.
\n" ); document.write( "I think someone typed the wrong question, and what should have been asked is \"write the equation for the ellipse\".
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\n" ); document.write( "Form the coordinates of the vertices, you can find the coordinates (h,v) of the center.
\n" ); document.write( "The center is midway between the vertices, so averaging the coordinates of the vertices, you find the coordinates of the center:
\n" ); document.write( "\"h=%28-3%2B%28-3%29%29%2F2=%28-6%29%2F2=-3\" (averaging the x-coordinates of the vertices),
\n" ); document.write( "and \"v=%285%2B%28-5%29%29%2F2=0%2F2=0\" (averaging the y-coordinates of the vertices).
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\n" ); document.write( "Form the coordinates of the foci, you can find the coordinates (h,v) of the center (also by averaging, the same way as done for the vertices).
\n" ); document.write( "
\n" ); document.write( "You need all (or most) of that information to figure out the equation for the ellipse.
\n" ); document.write( "Your ellipse has the center, vertices, and foci on the vertical line \"x=-3\" , and looks like this:
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\n" ); document.write( "The distance from the center to each vertex is usually called the \"semi-major axis\".
\n" ); document.write( "It is represented by the letter \"a\" , and in this case \"a=5\".
\n" ); document.write( "The distance from the center to each focus is usually called the \"focal distance\", and is represented by the letter \"c\" .
\n" ); document.write( "In this case \"c=4\" .
\n" ); document.write( "There is another important quantity, often called the \"semi-minor axis\", represented by the letter \"b\" .
\n" ); document.write( "The quantities \"a\" , \"b\" , and \"c\" are related by
\n" ); document.write( "\"a%5E2=b%5E2%2Bc%5E2\"
\n" ); document.write( "In this case, with \"a=5\" and \"c=4\" ,
\n" ); document.write( "\"5%5E2=b%5E2%2B4%5E2\"
\n" ); document.write( "\"25=b%5E2%2B16\"
\n" ); document.write( "\"25-16=b%5E2\"
\n" ); document.write( "\"b%5E2=9\"
\n" ); document.write( "When you know the coordinates of the center, (h,v),
\n" ); document.write( "know that the major axis is vertical
\n" ); document.write( "(center, vertices, and foci have the same x-coordinate),
\n" ); document.write( "and know \"a%5E2\" and \"b%5E2\" ,
\n" ); document.write( "you can write the equation of the ellipse as
\n" ); document.write( "\"%28x-h%29%5E2%2Fb%5E2%2B%28y-v%29%5E2%2Fa%5E2=1\"
\n" ); document.write( "In this case,
\n" ); document.write( "\"%28x-3%29%5E2%2F9%2B%28y-0%29%5E2%2F5%5E2=1\" ---> \"highlight%28%28x-3%29%5E2%2F9%2By%5E2%2F25=1%29\"
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