document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1159133>Question 1159133</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The function F(T) = -5T^2 + 10T + 40  models the height of a rocket shot into the air from a platform, where<BR>\n" );
document.write( "is the height of the rocket from the ground, in metres, and t is the time in seconds.<BR>\n" );
document.write( "a. what is the height of the platform?<BR>\n" );
document.write( "b. when does the rocket land? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #782123 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=782123\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> the height of the platform is the constant 40 m.<BR>\n" );
document.write( "the landing point is found by taking the positive root of -5t^2+10t+40=0<BR>\n" );
document.write( "or t^2-2t-8=0<BR>\n" );
document.write( "(t-4)(t+2)=0<BR>\n" );
document.write( "t= 4 seconds\r<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=graph%28300%2C300%2C-5%2C5%2C-20%2C60%2C-5x%5E2%2B10x%2B40%29 ALIGN=MIDDLE  ALT=\"graph%28300%2C300%2C-5%2C5%2C-20%2C60%2C-5x%5E2%2B10x%2B40%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );