document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1053466>Question 1053466</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A toy airplane flies according to the formula d(t)=5+20t-t^2 where d(t) is in meters and t is in seconds. How long will the toy airplane take to reach a distance of 100 meters from the person who controls it? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #668709 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=668709\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d%28t%29+=+-t%5E2+%2B+20t+%2B+5+ ALIGN=MIDDLE  ALT=\"+d%28t%29+=+-t%5E2+%2B+20t+%2B+5+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "given:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d%28t%29+=+100+ ALIGN=MIDDLE  ALT=\"+d%28t%29+=+100+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+100+=+-t%5E2+%2B+20t+%2B+5+ ALIGN=MIDDLE  ALT=\"+100+=+-t%5E2+%2B+20t+%2B+5+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+-t%5E2+%2B+20t+-+95+=+0+ ALIGN=MIDDLE  ALT=\"+-t%5E2+%2B+20t+-+95+=+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-------------------------<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+ ALIGN=MIDDLE  ALT=\"+t+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+a+=+-1+ ALIGN=MIDDLE  ALT=\"+a+=+-1+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+b+=+20+ ALIGN=MIDDLE  ALT=\"+b+=+20+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+c+=+-95+ ALIGN=MIDDLE  ALT=\"+c+=+-95+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+%28+-20+%2B-+sqrt%28+20%5E2-4%2A%28-1%29%2A%28-95%29+%29%29%2F%282%2A%28-1%29%29+ ALIGN=MIDDLE  ALT=\"+t+=+%28+-20+%2B-+sqrt%28+20%5E2-4%2A%28-1%29%2A%28-95%29+%29%29%2F%282%2A%28-1%29%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+%28+-20+%2B-+sqrt%28+400+-+380+%29%29%2F%28+%28-2%29+%29+ ALIGN=MIDDLE  ALT=\"+t+=+%28+-20+%2B-+sqrt%28+400+-+380+%29%29%2F%28+%28-2%29+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+%28+-20+%2B-+sqrt%28+20+%29%29%2F%28+%28-2%29+%29+ ALIGN=MIDDLE  ALT=\"+t+=+%28+-20+%2B-+sqrt%28+20+%29%29%2F%28+%28-2%29+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+%28+-20+-+4.472+%29+%2F+%28-2%29+ ALIGN=MIDDLE  ALT=\"+t+=+%28+-20+-+4.472+%29+%2F+%28-2%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+24.472+%2F+2+ ALIGN=MIDDLE  ALT=\"+t+=+24.472+%2F+2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+12.236+ ALIGN=MIDDLE  ALT=\"+t+=+12.236+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "and also:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+%28+-20+%2B+4.472+%29%2F%28-2%29+ ALIGN=MIDDLE  ALT=\"+t+=+%28+-20+%2B+4.472+%29%2F%28-2%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+15.528%2F2+ ALIGN=MIDDLE  ALT=\"+t+=+15.528%2F2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+7.764+ ALIGN=MIDDLE  ALT=\"+t+=+7.764+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "After 7.764 sec and 12.236 sec the toy plane is 100 m<BR>\n" );
document.write( "from the controler<BR>\n" );
document.write( "--------------------<BR>\n" );
document.write( "Heres the plot:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+graph%28+500%2C+500%2C+-4%2C+40%2C+-15%2C+150%2C+-x%5E2+%2B+20x+%2B+5+%29+ ALIGN=MIDDLE  ALT=\"+graph%28+500%2C+500%2C+-4%2C+40%2C+-15%2C+150%2C+-x%5E2+%2B+20x+%2B+5+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Note that the peak is at <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+10+sec+ ALIGN=MIDDLE  ALT=\"+t+=+10+sec+\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+d+=+105+ ALIGN=MIDDLE  ALT=\"+d+=+105+\"   DISABLED_style= \"max-width:90%; height:auto;\" > m<BR>\n" );
document.write( "--------------<BR>\n" );
document.write( "The times I came up with should be below and above <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+10+ ALIGN=MIDDLE  ALT=\"+t+=+10+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "by the same amount<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+10+-+7.764+=+2.236+ ALIGN=MIDDLE  ALT=\"+10+-+7.764+=+2.236+\"   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=+12.236+-+10+=+2.236+ ALIGN=MIDDLE  ALT=\"+12.236+-+10+=+2.236+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "OK </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );