document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=430270>Question 430270</A>: <I><SPAN STYLE=\"word-break: break-all;\"> write an equation is standard form for the ellipse with foci(7,0) and (_7,0) and y-intercepts of 2 and -2 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #298813 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=298813\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> write an equation is standard form for the ellipse with foci(7,0) and (_7,0) and y-intercepts of 2 and -2<BR>\n" );
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document.write( "Standard form of an ellipse with horizontal major axis, (this case): (x-h)^2/a^2+(y-k)^2/b^2=1<BR>\n" );
document.write( "Given foci coordinates show the y-coordinate of the center=0<BR>\n" );
document.write( "y-intercepts of 2 & -2 show that the x=coordinate of the center is also=0<BR>\n" );
document.write( "so center of ellipse is at (0,0)<BR>\n" );
document.write( "b=2<BR>\n" );
document.write( "b^2=4<BR>\n" );
document.write( "c=foci=7<BR>\n" );
document.write( "c^2=a^2-b^2<BR>\n" );
document.write( "a^2=c^2+b^2=49+4=53<BR>\n" );
document.write( "a=sqrt(53)=7.28<BR>\n" );
document.write( "Equation of ellipse:<BR>\n" );
document.write( "x^2/53+y^2/4=1<BR>\n" );
document.write( "Graph below can visually confirm the answers obtained.<BR>\n" );
document.write( "..<BR>\n" );
document.write( "y=+-((1-x^2/53)4)^.5<BR>\n" );
document.write( " <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+graph%28+300%2C+300%2C+-10%2C+10%2C+-10%2C+10%2C+%28%281-x%5E2%2F53%294%29%5E.5%2C-%28%281-x%5E2%2F53%294%29%5E.5%29+ ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" >  </SPAN>\n" );
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