document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1088905>Question 1088905</A>: <I><SPAN STYLE=\"word-break: break-all;\"> H(t)= -5t^2 + at + b<BR>\n" );
document.write( "At time t=0, a ball was thrown upward from the top of a building. Before the ball hit the ground, its height h(t), in feet, at the time t seconds is given by the function above. A and b are constants. If the ball reached its maximum height of 125 feet at time t=3, what could be the height of the building? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #703223 by </B><A HREF=/tutors/aboutme.mpl?userid=jorel1380><B>jorel1380(3719)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jorel1380><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=jorel1380><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=703223\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> If h(t)=-5t²+at+b, then the maximum height is achieved at -a/2(-5) for t. So:<BR>\n" );
document.write( "3=-a/-10<BR>\n" );
document.write( "-a=-30<BR>\n" );
document.write( "a=30<BR>\n" );
document.write( "So, to find the height of the building, b, we have<BR>\n" );
document.write( "125=-5(3²)+30(3)+b<BR>\n" );
document.write( "125=90-45+b<BR>\n" );
document.write( "b=80 ft. as the height of the building<BR>\n" );
document.write( "&#9786;&#9786;&#9786;&#9786; </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );