document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=81488>Question 81488</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0078656095/algebrahomeworkh>Algebra 2</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> I can not figure out how to write an equation for parabola  <BR>\n" );
document.write( "   focus (3,8),directrix y=4 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #58340 by </B><A HREF=/tutors/aboutme.mpl?userid=scott8148><B>scott8148(6628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=scott8148><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=scott8148><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=58340\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> a parabola is made up of points that are equidistant from a given point (focus) and a given line (directrix)\r<BR>\n" );
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document.write( "the \"distance formula\" gives the distance between (x,y) and (3,8) as <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%28%28x-3%29%5E2%2B%28y-8%29%5E2%29 ALIGN=MIDDLE  ALT=\"sqrt%28%28x-3%29%5E2%2B%28y-8%29%5E2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "the distance between (x,y) and y=4 is y-4 ... x is not involved\r<BR>\n" );
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document.write( "setting these equal gives <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%28%28x-3%29%5E2%2B%28y-8%29%5E2%29=y-4 ALIGN=MIDDLE  ALT=\"sqrt%28%28x-3%29%5E2%2B%28y-8%29%5E2%29=y-4\"   DISABLED_style= \"max-width:90%; height:auto;\" > ... squaring both sides gives <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28x-3%29%5E2%2B%28y-8%29%5E2=%28y-4%29%5E2 ALIGN=MIDDLE  ALT=\"%28x-3%29%5E2%2B%28y-8%29%5E2=%28y-4%29%5E2\"   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=x%5E2-6x%2B9%2By%5E2-16y%2B64=y%5E2-8y%2B16 ALIGN=MIDDLE  ALT=\"x%5E2-6x%2B9%2By%5E2-16y%2B64=y%5E2-8y%2B16\"   DISABLED_style= \"max-width:90%; height:auto;\" > ... <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5E2-9x%2B64%2B9-16=y%5E2-8y-y%5E2%2B16y ALIGN=MIDDLE  ALT=\"x%5E2-9x%2B64%2B9-16=y%5E2-8y-y%5E2%2B16y\"   DISABLED_style= \"max-width:90%; height:auto;\" > ... <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5E2-9x%2B57=8y ALIGN=MIDDLE  ALT=\"x%5E2-9x%2B57=8y\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "so <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=x%5E2%2F8-9x%2F8%2B57%2F8 ALIGN=MIDDLE  ALT=\"y=x%5E2%2F8-9x%2F8%2B57%2F8\"   DISABLED_style= \"max-width:90%; height:auto;\" >  ........THIS ANSWER HAS BEEN CORRECTED (with my apologies) </SPAN>\n" );
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