document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1205519>Question 1205519</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The equation H(T)=-16x^2+64x+9 models the height, H , in feet, of a model rocket t<BR>\n" );
document.write( "seconds after it has been launched from 9 feet above the ground. How many seconds after launching the rocket will it reach its maximum height?<BR>\n" );
document.write( "A.1 seconds<BR>\n" );
document.write( "B.2 seconds<BR>\n" );
document.write( "C.2.5 seconds<BR>\n" );
document.write( "D.3 seconds  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #842375 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=842375\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The equation H(T)=-16x^2+64x+9 models the height, H , in feet, of a model rocket t<BR>\n" );
document.write( "seconds after it has been launched from 9 feet above the ground. How many seconds after launching the rocket will it reach its maximum height?<BR>\n" );
document.write( "-------------<BR>\n" );
document.write( "There are no T's in the function.<BR>\n" );
document.write( "Assuming you mean H(T)=-16T^2 + 64T + 9<BR>\n" );
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document.write( "At the apogee, max height, the vertical speed is zero (0).<BR>\n" );
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document.write( "H(T)=-16T^2 + 64T + 9<BR>\n" );
document.write( "H'(T) = -32T + 64 = 0  ----- THE 1ST DERIVATIVE<BR>\n" );
document.write( "T = 2 seconds<BR>\n" );
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