document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=557598>Question 557598</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find an equation for an ellipse with major axis of length 10 and foci at (0,-4) and (-4,-4). </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #362762 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=362762\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Find an equation for an ellipse with major axis of length 10 and foci at (0,-4) and (-4,-4)<BR>\n" );
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document.write( "Standard form of equation for ellipse with horizontal major axis: <BR>\n" );
document.write( "(x-h)^2/a^2+(y-k)^2/b^2, a>b, (h,k) being the (x,y) coordinates of the center.<BR>\n" );
document.write( "..<BR>\n" );
document.write( "For given equation:<BR>\n" );
document.write( "major axis: horizontal (from foci data)<BR>\n" );
document.write( "y-coordinate of center:-4 (from foci data)<BR>\n" );
document.write( "x-coordinate of center:-2 (midway between foci)<BR>\n" );
document.write( "center: (-2,-4)<BR>\n" );
document.write( "length of horizontal major axis=10=2a<BR>\n" );
document.write( "a=5<BR>\n" );
document.write( "a^2=25<BR>\n" );
document.write( "c=2 (distance from center to focus)<BR>\n" );
document.write( "c^2=4<BR>\n" );
document.write( "c^2=a^2-b^2<BR>\n" );
document.write( "b^2=a^2-c^2=25-4=21<BR>\n" );
document.write( "b=&#8730;21&#8776;4.58<BR>\n" );
document.write( "Equation of given ellipse:<BR>\n" );
document.write( "(x+2)^2/25+(y+4)^2/21 </SPAN>\n" );
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