document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1080588>Question 1080588</A>: <I><SPAN STYLE=\"word-break: break-all;\"> What type of directrix does this conic have? r = 4/-2-cos&#952; or https://s10.postimg.org/kbq3bkdpl/r_-2_-cos.png <BR>\n" );
document.write( "A.) Vertical<BR>\n" );
document.write( "B.) Horizontal<BR>\n" );
document.write( "C.) Oblique<BR>\n" );
document.write( "D.) No directrix. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #694715 by </B><A HREF=/tutors/aboutme.mpl?userid=MathLover1><B>MathLover1(20850)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=MathLover1><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=MathLover1><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=694715\">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=r+=+4%2F%28-2-cos%28theta%29%29 ALIGN=MIDDLE  ALT=\"r+=+4%2F%28-2-cos%28theta%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r+=+4%2F-2%281%2B%281%2F2%29cos%28theta%29%29 ALIGN=MIDDLE  ALT=\"r+=+4%2F-2%281%2B%281%2F2%29cos%28theta%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r+=+-2%2F%281%2B%281%2F2%29cos%28theta%29%29 ALIGN=MIDDLE  ALT=\"r+=+-2%2F%281%2B%281%2F2%29cos%28theta%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >.....compare to <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r+=+ed%2F%281%2B%28e%29cos%28theta%29%29 ALIGN=MIDDLE  ALT=\"r+=+ed%2F%281%2B%28e%29cos%28theta%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > and you see that:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=ed+=+-2 ALIGN=MIDDLE  ALT=\"ed+=+-2\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=e+=+1%2F2 ALIGN=MIDDLE  ALT=\"e+=+1%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28-1%2F2%29d+=+2 ALIGN=MIDDLE  ALT=\"%28-1%2F2%29d+=+2\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d+=+-2%2F%281%2F2%29 ALIGN=MIDDLE  ALT=\"d+=+-2%2F%281%2F2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d+=+-4 ALIGN=MIDDLE  ALT=\"d+=+-4\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Since <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=e+%3C+1 ALIGN=MIDDLE  ALT=\"e+%3C+1\"   DISABLED_style= \"max-width:90%; height:auto;\" >, we have the equation of an ellipse. The form of the equation tells us that the directrix is perpendicular to the polar axis and that its Cartesian equation is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+-4 ALIGN=MIDDLE  ALT=\"x+=+-4\"   DISABLED_style= \"max-width:90%; height:auto;\" > which is vertical line.\r<BR>\n" );
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document.write( "so, answer is: A.) <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=Vertical ALIGN=MIDDLE  ALT=\"Vertical\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( " </SPAN>\n" );
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