document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=624989>Question 624989</A>: <I><SPAN STYLE=\"word-break: break-all;\"> please help me solve this (What is the equation of a parabola with a vertex at (1, -1) and a 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 #393438 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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=393438\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> please help me solve this (What is the equation of a parabola with a vertex at (1, -1) and a directrix y = 4<BR>\n" );
document.write( "Form of equation for a parabola that opens downwards: (x-h)^2=-4p(y-k), (h,k)=(x,y) coordinates of the vertex.<BR>\n" );
document.write( "For given parabola:<BR>\n" );
document.write( "vertex: (1,-1)<BR>\n" );
document.write( "axis of symmetry: x=1<BR>\n" );
document.write( "p=5 (-1 to 4) (distance from vertex to directrix on the axis of symmetry)<BR>\n" );
document.write( "4p=20<BR>\n" );
document.write( "equation: (x-1)^2=-20(y+1) </SPAN>\n" );
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