document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=243249>Question 243249</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Estimating the age of a fossil- a fossilized leaf contains 70% of its normal amount of carbon 14.<BR>\n" );
document.write( "a) how old is the fossil<BR>\n" );
document.write( "b) using a graphing utility, graph the relation between the percentage of carbon 14 remaining and time.<BR>\n" );
document.write( "c) using intersect, determine the time that elapses until half the carbon 14 remains<BR>\n" );
document.write( "d) verify the answer found in part (a)\r<BR>\n" );
document.write( "\n" );
document.write( "I know this problem seem long but i just want to say thanks for your help.  I really appreciate it. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #178270 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=178270\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Estimating the age of a fossil- a fossilized leaf contains 70% of its normal amount of carbon 14.<BR>\n" );
document.write( "The carbon 14 dating formula: A = Ao*e^-.000124t<BR>\n" );
document.write( "where<BR>\n" );
document.write( "A = amt remaining after t years<BR>\n" );
document.write( "Ao = initial amt<BR>\n" );
document.write( "t = time in years<BR>\n" );
document.write( ":<BR>\n" );
document.write( "a) how old is the fossil<BR>\n" );
document.write( "Ao=1; A = .7<BR>\n" );
document.write( "e^-.000124t = .7<BR>\n" );
document.write( "-.000124t*ln(e) = ln(.7)<BR>\n" );
document.write( "-.000124t = -.356675<BR>\n" );
document.write( "t = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%28-.356675%29%2F%28-.000124%29 ALIGN=MIDDLE  ALT=\"%28-.356675%29%2F%28-.000124%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "t = 2876.4 years<BR>\n" );
document.write( ":<BR>\n" );
document.write( "b) using a graphing utility, graph the relation between the percentage of carbon 14 remaining and time.<BR>\n" );
document.write( "Graph: y = e^(-.000124x)<BR>\n" );
document.write( "looks something like this:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+graph%28+300%2C+200%2C+-2000%2C+8000%2C+-.5%2C+1.2%2C+e%5E%28-.000124x%29+%29+ ALIGN=MIDDLE  ALT=\"+graph%28+300%2C+200%2C+-2000%2C+8000%2C+-.5%2C+1.2%2C+e%5E%28-.000124x%29+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "where x=0, y=1<BR>\n" );
document.write( "y scale: 0 to 1; x scale: 0 to 8000 yrs<BR>\n" );
document.write( ":<BR>\n" );
document.write( "c) using intersect, determine the time that elapses until half the carbon 14 remains<BR>\n" );
document.write( "About 5600 yrs for half to remain<BR>\n" );
document.write( ":<BR>\n" );
document.write( "d) verify the answer found in part (a)<BR>\n" );
document.write( "In your graphing utility, enter x=2876, y should = .7  </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );