document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=981571>Question 981571</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A radio active isotope decays according to the exponential decay equation where t is in days. <BR>\n" );
document.write( "Round to the thousandths place. <BR>\n" );
document.write( "For the half life: The half life is the solution (t) of the equation :<BR>\n" );
document.write( "a2=ae^&#8722;4.132t </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #602554 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=602554\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> a=ao e ^(-4.132 t)\r<BR>\n" );
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document.write( "a=(1/2) ao<BR>\n" );
document.write( "Therefore <BR>\n" );
document.write( "(1/2)=e^(-4.132 t)<BR>\n" );
document.write( "ln of both sides<BR>\n" );
document.write( "-0.693= -4.132 t<BR>\n" );
document.write( "divide by (-4.132)<BR>\n" );
document.write( "t=0.1677 days\r<BR>\n" );
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document.write( "check<BR>\n" );
document.write( "-4.132*0.1677=-0.6929<BR>\n" );
document.write( "e^-0.6929=0.5 </SPAN>\n" );
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