document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=669376>Question 669376</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A ball is thrown vertically upward from the top of a cliff. The height of the ball is modeled by the function h(t) = 65 + 10t - 5t^2, where h(t) is the height in metres and t is the time in seconds. Determine when the ball reaches its maximum height.<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #416349 by </B><A HREF=/tutors/aboutme.mpl?userid=nerdybill><B>nerdybill(7384)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=nerdybill><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=nerdybill><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=416349\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A ball is thrown vertically upward from the top of a cliff. The height of the ball is modeled by the function h(t) = 65 + 10t - 5t^2, where h(t) is the height in metres and t is the time in seconds. Determine when the ball reaches its maximum height.<BR>\n" );
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document.write( "equation is<BR>\n" );
document.write( "h(t) = 65 + 10t - 5t^2<BR>\n" );
document.write( "h(t) = -5t^2 + 10t + 65<BR>\n" );
document.write( "the max height is reached at the vertex.<BR>\n" );
document.write( "the value of t at the vertex is:<BR>\n" );
document.write( "t = -b/(2a)<BR>\n" );
document.write( "t = -10/(2(-10))<BR>\n" );
document.write( "t = -10/(-20)<BR>\n" );
document.write( "t = 10/(20)<BR>\n" );
document.write( "t = 1/2 seconds (answer) </SPAN>\n" );
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