document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=961582>Question 961582</A>: <I><SPAN STYLE=\"word-break: break-all;\"> x^2 + 3y = 0<BR>\n" );
document.write( "Whats the focus and directrix? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #587560 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><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=587560\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=-%281%2F3%29x%5E2 ALIGN=MIDDLE  ALT=\"y=-%281%2F3%29x%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "or<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5E2=-3y ALIGN=MIDDLE  ALT=\"x%5E2=-3y\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Derive the formula for a parabola and compare.\r<BR>\n" );
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document.write( "The derivation uses directrix and focus.\r<BR>\n" );
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document.write( "Compare to <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5E2=4py ALIGN=MIDDLE  ALT=\"x%5E2=4py\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-3=4p ALIGN=MIDDLE  ALT=\"-3=4p\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=p=-3%2F4 ALIGN=MIDDLE  ALT=\"p=-3%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "The meaning for p is the distance from directrix or focus to the vertex.  The given parabola is inverted, so the vertex is a maximum point with vertical symmetry axis.  This one has vertex at the origin, (0,0), as seen from no add or subtract from x and no add or subtract from y.  The focus is (0,-3/4) and the directrix is y=3/4. </SPAN>\n" );
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