document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1021026>Question 1021026</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I need help with this problem. Please help me and show all work. Thanks\r<BR>\n" );
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document.write( "A person standing close to the edge on top of a 144-foot building throws a ball vertically upward. The quadratic function h(t)=&#8722;16t^2+128t+144<BR>\n" );
document.write( "h(t)=-16t^2+128t+144 models the ball's height about the ground, h(t)<BR>\n" );
document.write( " in feet, t seconds after it was thrown.\r<BR>\n" );
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document.write( " a) What is the maximum height of the ball?\r<BR>\n" );
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document.write( "   _________feet\r<BR>\n" );
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document.write( " b) How many seconds does it take until the ball hits the ground?\r<BR>\n" );
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document.write( "   _________ seconds </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #636871 by </B><A HREF=/tutors/aboutme.mpl?userid=MathTherapy><B>MathTherapy(10552)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=MathTherapy><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=MathTherapy><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=636871\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <BR>\n" );
document.write( "I need help with this problem. Please help me and show all work. Thanks\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "A person standing close to the edge on top of a 144-foot building throws a ball vertically upward. The quadratic function h(t)=&#8722;16t^2+128t+144<BR>\n" );
document.write( "h(t)=-16t^2+128t+144 models the ball's height about the ground, h(t)<BR>\n" );
document.write( " in feet, t seconds after it was thrown.\r<BR>\n" );
document.write( "\n" );
document.write( " a) What is the maximum height of the ball?\r<BR>\n" );
document.write( "\n" );
document.write( "   _________feet\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( " b) How many seconds does it take until the ball hits the ground?\r<BR>\n" );
document.write( "\n" );
document.write( "   _________ seconds<BR>\n" );
document.write( "<PRE STYLE=\"white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;\">Maximum height occurs at <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%28-+b%29%2F%282a%29 ALIGN=MIDDLE  ALT=\"x+=+%28-+b%29%2F%282a%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, or at <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+%28-+128%29%2F%282+%2A+-+16%29 ALIGN=MIDDLE  ALT=\"x+=+%28-+128%29%2F%282+%2A+-+16%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, or at: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+4 ALIGN=MIDDLE  ALT=\"x+=+4\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Maximum height at <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x+=+4 ALIGN=MIDDLE  ALT=\"x+=+4\"   DISABLED_style= \"max-width:90%; height:auto;\" > is: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y+=+-+16%284%29%5E2+%2B+128%284%29+%2B+144 ALIGN=MIDDLE  ALT=\"y+=+-+16%284%29%5E2+%2B+128%284%29+%2B+144\"   DISABLED_style= \"max-width:90%; height:auto;\" >, or <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y+=+-+256+%2B+512+%2B+144 ALIGN=MIDDLE  ALT=\"y+=+-+256+%2B+512+%2B+144\"   DISABLED_style= \"max-width:90%; height:auto;\" >, or maximum height reached = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight_green%28matrix%281%2C2%2C+400%2C+ft%29%29 ALIGN=MIDDLE  ALT=\"highlight_green%28matrix%281%2C2%2C+400%2C+ft%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > \r<BR>\n" );
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document.write( "Ball hits the ground when y, or height = 0, so we get:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0+=+-+16t%5E2+%2B+128t+%2B+144 ALIGN=MIDDLE  ALT=\"0+=+-+16t%5E2+%2B+128t+%2B+144\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-+16%280%29+=+-+16%28t%5E2+-+8t+-+9%29 ALIGN=MIDDLE  ALT=\"-+16%280%29+=+-+16%28t%5E2+-+8t+-+9%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > ---- Factoring out GCF, - 16<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=0+=+t%5E2+-+8t+-+9 ALIGN=MIDDLE  ALT=\"0+=+t%5E2+-+8t+-+9\"   DISABLED_style= \"max-width:90%; height:auto;\" >  <BR>\n" );
document.write( "0 = (t - 9)(t + 1)<BR>\n" );
document.write( "0 = t - 9        OR          0 = t + 1<BR>\n" );
document.write( "t, or time it takes ball to hit the ground = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight_green%28matrix%281%2C2%2C+9%2C+seconds%29%29 ALIGN=MIDDLE  ALT=\"highlight_green%28matrix%281%2C2%2C+9%2C+seconds%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >            OR          - 1 = t (ignore)  </SPAN>\n" );
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