document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=910873>Question 910873</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A model rocket is shot vertically upward with an initial velocity of 288 ft./sec. The function given by h(t) = -16t2 + 128t relates the rocket’s height h(t) in feet to the time t after launch, in seconds. Find h(0) Find h(5) Find the t-intercepts and interpret their meaning in the context of the problem Find the times at which the rocket is at a height of 1152 feet. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #552734 by </B><A HREF=/tutors/aboutme.mpl?userid=ewatrrr><B>ewatrrr(24785)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ewatrrr><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=ewatrrr><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=552734\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  h(t) = -16t^2 + 288t <BR>\n" );
document.write( " h(t) = -16(t-9)^2 + 1296 Pt(9,1296) max point<BR>\n" );
document.write( "....<BR>\n" );
document.write( "0  = -16(t-4)^2 + 1296<BR>\n" );
document.write( "16(t-4)^2 = 1296<BR>\n" );
document.write( "(t-4)^2 = 81<BR>\n" );
document.write( " t = 4 ± 9<BR>\n" );
document.write( "t-intercepts: -5, 13<BR>\n" );
document.write( "....<BR>\n" );
document.write( "h(0) = 0<BR>\n" );
document.write( "h(5) = plug and play <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-16%2A25+%2B+288%2A5 ALIGN=MIDDLE  ALT=\"-16%2A25+%2B+288%2A5\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "....<BR>\n" );
document.write( "1152 = -16t^2 + 288t <BR>\n" );
document.write( "16t^2 - 288t +1152 = 0<BR>\n" );
document.write( "t^2 -18t + 72<BR>\n" );
document.write( "(t-12)(t-6) = 0<BR>\n" );
document.write( "t is 6, 12<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );