document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=450434>Question 450434</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If given the equation of a parabola, how do i find the focus? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #309843 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=309843\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> If given the equation of a parabola, how do i find the focus?<BR>\n" );
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document.write( "There are 4 basic equations for the parabola from which you can find the focus as follows:<BR>\n" );
document.write( "1) x^2=4py (parabola opens upwards, axis of symmetry vertical)<BR>\n" );
document.write( "2) x^2=-4py  (parabola opens downwards, axis of symmetry vertical)<BR>\n" );
document.write( "3) y^2=4px  (parabola opens rightwards, axis of symmetry horizontal)<BR>\n" );
document.write( "4) y^2=-4px  (parabola opens leftwards, axis of symmetry horizontal)<BR>\n" );
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document.write( "In all four cases, if you find p, you can find the focus. 4p is the coefficient of x or y as the case might be.  p is also the distance from vertex to focus and from vertex to directrix on the axis of symmetry. If you know 2 out of the 3 items( p, vertex, and directrix) you should be able to find the focus. </SPAN>\n" );
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