document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=628918>Question 628918</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A focal point of the elipse <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A+focal+point+of+the+elipse+ ALIGN=MIDDLE  ALT=\"A+focal+point+of+the+elipse+\"   DISABLED_style= \"max-width:90%; height:auto;\" >((x+3)^2)/16)+(y-1)^2)/4)=1 is:<BR>\n" );
document.write( "a.) (-1,1)<BR>\n" );
document.write( "b.) (-3-2 radical 3, 1)<BR>\n" );
document.write( "c.) (-7,1)<BR>\n" );
document.write( "d.) 3+2 radical 3, 1)\r<BR>\n" );
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document.write( "* note: when ever i have entered the equation in to graph it it keeps saying 1/16 (x+3) but that is not correct it is x+3^2 all over 16. \r<BR>\n" );
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document.write( "I have worked it some way but I dont know how to continue it. I have:\r<BR>\n" );
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document.write( "Centre: (-3,1)<BR>\n" );
document.write( "a=16<BR>\n" );
document.write( "b=3<BR>\n" );
document.write( "c=15.716\r<BR>\n" );
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document.write( "but i dont know how to find the focal point.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #395895 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=395895\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Find a focal point of the ellipse:<BR>\n" );
document.write( "((x+3)^2)/16)+(y-1)^2)/4)=1<BR>\n" );
document.write( "This is an equation of an ellipse with horizontal major axis:<BR>\n" );
document.write( "Its standard form: (x-h)^2/a^2+(y-k)^2/b^2=1, (a>b), (h,k)=(x,y) coordinates of center<BR>\n" );
document.write( "For given ellipse:<BR>\n" );
document.write( "center(-3,1)<BR>\n" );
document.write( "a^2=16<BR>\n" );
document.write( "a=&#8730;16=4<BR>\n" );
document.write( "b^2=4<BR>\n" );
document.write( "b=&#8730;4=2<BR>\n" );
document.write( "c^2=a^2-b^2=16-12=4<BR>\n" );
document.write( "c=&#8730;4=2<BR>\n" );
document.write( "Foci: (Both focal points)=(-3±c,1)=(-3±2,1)=(-5,1) and (-1,1)<BR>\n" );
document.write( "answer a is the correct answer </SPAN>\n" );
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