document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1075737>Question 1075737</A>: <I><SPAN STYLE=\"word-break: break-all;\"> What is the equation in standard form for the parabola with vertex (0,0) and directrix you= -4<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #690373 by </B><A HREF=/tutors/aboutme.mpl?userid=josmiceli><B>josmiceli(19441)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josmiceli><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=josmiceli><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=690373\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> If the form of the equation is<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+y+=+a%2Ax%5E2+%2B+bx+%2B+c+ ALIGN=MIDDLE  ALT=\"+y+=+a%2Ax%5E2+%2B+bx+%2B+c+\"   DISABLED_style= \"max-width:90%; height:auto;\" >, then the <BR>\n" );
document.write( "x-value of the vertex is at <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+-b%2F%282a%29+ ALIGN=MIDDLE  ALT=\"+-b%2F%282a%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Since the vertex is (0,0), then<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+-b%2F%282a%29+=+0+ ALIGN=MIDDLE  ALT=\"+-b%2F%282a%29+=+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" > and<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b+=+0+ ALIGN=MIDDLE  ALT=\"+b+=+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+y+=+a%2Ax%5E2+%2B+c+ ALIGN=MIDDLE  ALT=\"+y+=+a%2Ax%5E2+%2B+c+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+y+=+a%2A0+%2B+c+ ALIGN=MIDDLE  ALT=\"+y+=+a%2A0+%2B+c+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+y+=+c+ ALIGN=MIDDLE  ALT=\"+y+=+c+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and since the vertex is at (0,0)<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+c+=+0+ ALIGN=MIDDLE  ALT=\"+c+=+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "So far I have:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+y+=+a%2Ax%5E2+ ALIGN=MIDDLE  ALT=\"+y+=+a%2Ax%5E2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "------------------<BR>\n" );
document.write( "Let the y-value of the focus = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+f+ ALIGN=MIDDLE  ALT=\"+f+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%28+f+%2B+%28-4%29+%29+%2F+2+=+0+ ALIGN=MIDDLE  ALT=\"+%28+f+%2B+%28-4%29+%29+%2F+2+=+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+f+-+4+=+0+ ALIGN=MIDDLE  ALT=\"+f+-+4+=+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+f+=+4+ ALIGN=MIDDLE  ALT=\"+f+=+4+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "The x-value of the focus will be the same as the vertex,<BR>\n" );
document.write( "so the focus is at ( 0,4 )<BR>\n" );
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document.write( "According to the formula, a parabola with focus ( x[f], y[f] )<BR>\n" );
document.write( "and directrix <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+y+=+d+ ALIGN=MIDDLE  ALT=\"+y+=+d+\"   DISABLED_style= \"max-width:90%; height:auto;\" > has the form<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%28+x+-+x%5Bf%5D+%29%5E2+%2B+y%5Bf%5D%5E2+-+d%5E2+=+2%2A%28+y%5Bf%5D+-+d+%29%2Ay+ ALIGN=MIDDLE  ALT=\"+%28+x+-+x%5Bf%5D+%29%5E2+%2B+y%5Bf%5D%5E2+-+d%5E2+=+2%2A%28+y%5Bf%5D+-+d+%29%2Ay+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%28+x+-+0+%29%5E2+%2B+4%5E2+-+%28-4%29%5E2+=+2%2A%28+4+-%28-4%29+%29%2Ay+%7D+ ALIGN=MIDDLE  ALT=\"+%28+x+-+0+%29%5E2+%2B+4%5E2+-+%28-4%29%5E2+=+2%2A%28+4+-%28-4%29+%29%2Ay+%7D+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x%5E2+%2B+16+-+16+=+2%2A8%2Ay+ ALIGN=MIDDLE  ALT=\"+x%5E2+%2B+16+-+16+=+2%2A8%2Ay+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+16y+=+x%5E2+ ALIGN=MIDDLE  ALT=\"+16y+=+x%5E2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+y+=+%281%2F16%29%2Ax%5E2+ ALIGN=MIDDLE  ALT=\"+y+=+%281%2F16%29%2Ax%5E2+\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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