document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=329756>Question 329756</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A rock is launched from a cannon its height, h(x), can be represented by a quadratic function in terms of time, x, in seconds.\r<BR>\n" );
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document.write( "After 1 second, the rock is 186 feet in the air after 2 seconds, it is 344 in the air. \r<BR>\n" );
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document.write( "Find the height, in feet,of the rock after 8 seconds in the air. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #236353 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=236353\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A rock is launched from a cannon its height, h(x), can be represented by a quadratic function in terms of time, x, in seconds.<BR>\n" );
document.write( "After 1 second, the rock is 186 feet in the air; after 2 seconds, it is 344 in the air.<BR>\n" );
document.write( "Find the height, in feet,of the rock after 8 seconds in the air.;<BR>\n" );
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document.write( "Using the form: ax^2 + bx + c = y<BR>\n" );
document.write( "y = h(x), c = 0<BR>\n" );
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document.write( "x=1; y=186<BR>\n" );
document.write( "a(1^2) + 1b = 186<BR>\n" );
document.write( "a + b = 186<BR>\n" );
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document.write( "x=2; y=344<BR>\n" );
document.write( "a(2^2) + 2b = 344<BR>\n" );
document.write( "4a + 2b = 344<BR>\n" );
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document.write( "Multiply the 1st equation by 2, subtract from the 2nd equation<BR>\n" );
document.write( "4a + 2b = 344<BR>\n" );
document.write( "2a + 2b = 372<BR>\n" );
document.write( "--------------Subtraction eliminates b, find a<BR>\n" );
document.write( "2a = -28<BR>\n" );
document.write( "a = -14<BR>\n" );
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document.write( "Find b using: a + b = 186<BR>\n" );
document.write( "-14 + b = 186<BR>\n" );
document.write( "b = 186 + 14<BR>\n" );
document.write( "b = 200<BR>\n" );
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document.write( "The equation: h(x) = -14x^2 + 200x <BR>\n" );
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document.write( "\"Find the height, in feet,of the rock after 8 seconds in the air.;<BR>\n" );
document.write( "x=8<BR>\n" );
document.write( "h(8) = -14(8^2) + 200(8)<BR>\n" );
document.write( "h(8) = -14(64) + 1600<BR>\n" );
document.write( "h(8) = -896 + 1600<BR>\n" );
document.write( "h(8) = 704 ft after 8 sec </SPAN>\n" );
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