document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=913811>Question 913811</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Can someone tell me what I'm supposed to do? I don't get it. I'm supposed to find the focus and directrix. <BR>\n" );
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document.write( "I have all of these formulas but I have no clue where to put what. It's starting to irritate me. A lot. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #554740 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39620)</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=554740\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> This is not a solution, but just advice:\r<BR>\n" );
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document.write( "Study how the equation of a parabola is derived using the distance formula, the meaning and use of focus and directrix, and the definition of a parabola.   Simplify the distance formula equation and check how the resulting formula appears.  That would be how to derive the equation of a parabola.\r<BR>\n" );
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document.write( "What you want to do is work in the other direction, so you would use the parts the resulting derived parabola equation to find the focus and directrix.\r<BR>\n" );
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document.write( "Like I say, this is advice or guidance, but not the answer you requested.<BR>\n" );
document.write( "Your textbook should show a very good derivation for the equation of a parabola.  Say if otherwise.\r<BR>\n" );
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document.write( "Note that in your second equation, the vertex would have moved from the standard reference (0,0) to  the new vertex point (-3,5). </SPAN>\n" );
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