document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=475246>Question 475246</A>: <I><SPAN STYLE=\"word-break: break-all;\"> What is the directrix of the parabola with equation -28y = x2? show work please? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #325871 by </B><A HREF=/tutors/aboutme.mpl?userid=robertb><B>robertb(5830)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=robertb><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/cgi-bin/show-face.mpl?user=robertb><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=325871\">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=-28y+=+x%5E2 ALIGN=MIDDLE  ALT=\"-28y+=+x%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" > ==> 4c = -28 ==> c = -7 (parabola is facing downward with vertex at (0,0)) ==> directrix is y = 7. </SPAN>\n" );
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