document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=65295>Question 65295</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Jim is a fisherman. He varies the depth at which he fishes according to the following function: D(t)= -t^2+10t where t is measured in hours. Estimate the time when he fishes at the greatest depth and tell me that depth. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #45848 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=45848\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> D(t)= -t^2+10t <BR>\n" );
document.write( "If this is put in the form<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=D%28t%29+=+at%5E2+%2B+bt+%2B+c ALIGN=MIDDLE  ALT=\"D%28t%29+=+at%5E2+%2B+bt+%2B+c\"   DISABLED_style= \"max-width:90%; height:auto;\" >, the the maximum 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;\" >,<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=D ALIGN=MIDDLE  ALT=\"D\"   DISABLED_style= \"max-width:90%; height:auto;\" >)<BR>\n" );
document.write( "b = +10<BR>\n" );
document.write( "a = -1<BR>\n" );
document.write( "-b/(2a) = -10/-2<BR>\n" );
document.write( "-10/-2 = 5<BR>\n" );
document.write( "D(5) = -(5)^2 + 10*5  <BR>\n" );
document.write( "D(5) = -25 + 50<BR>\n" );
document.write( "D(5) = 25<BR>\n" );
document.write( "so, the maximum is at (5,25)<BR>\n" );
document.write( "He fishes at a depth of 25 in 5 hours. Is D in units of feet?<BR>\n" );
document.write( "Problem didn't say.  </SPAN>\n" );
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