document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1044259>Question 1044259</A>: <I><SPAN STYLE=\"word-break: break-all;\">  light bulb of a parabolic reflector is placed at the focus of th reflector for better reflection. suppose that the reflector is 18 inches wide and 10 inches deep\r<BR>\n" );
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document.write( "what is the equation  of the parabola in the parabolic reflector? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #659580 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39617)</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=659580\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Imagine a cross section through the vertex and along the vertical symmetry axis and placed on a cartesian system putting the vertex as a minimum, on the Origin.\r<BR>\n" );
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document.write( "If 18 inches wide at top opening, and 10 inches deep, a point on the parabola is  (9,10).  The \"9\" because half of x component goes in one direction and the other half goes the other direction.  \r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=ax%5E2 ALIGN=MIDDLE  ALT=\"y=ax%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" >, and use the other one given or described point to find \"a\".<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a=y%2Fx%5E2 ALIGN=MIDDLE  ALT=\"a=y%2Fx%5E2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a=10%2F81 ALIGN=MIDDLE  ALT=\"a=10%2F81\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28y=%2810%2F81%29x%5E2%29 ALIGN=MIDDLE  ALT=\"highlight%28y=%2810%2F81%29x%5E2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "Notice that the question does not involve the focus, although mentioned in the description.  The focus can be found. </SPAN>\n" );
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