document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1156506>Question 1156506</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An isotype of Sodium, Na-24, has a half life of 10h. If a sample contains 400 units of Na-24, the exponential function to model this is y=400(1/2)^x.\r<BR>\n" );
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document.write( "What does the variable y represent in this situation?<BR>\n" );
document.write( "What does the variable x represent in this situation? \r<BR>\n" );
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document.write( "Im confused and don't know how to figure this out.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #779224 by </B><A HREF=/tutors/aboutme.mpl?userid=ikleyn><B>ikleyn(52803)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ikleyn><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=ikleyn><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=779224\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> .<BR>\n" );
document.write( "An <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28cross%28isotype%29%29 ALIGN=MIDDLE  ALT=\"highlight%28cross%28isotype%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > <U>isotope</U> of Sodium, Na-24, has a half life of 10h. <BR>\n" );
document.write( "If a sample contains 400 units of Na-24, the exponential function to model this is y=400(1/2)^x.\r<BR>\n" );
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document.write( "What does the variable y represent in this situation?<BR>\n" );
document.write( "What does the variable x represent in this situation? \r<BR>\n" );
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document.write( "Im confused and don't know how to figure this out. <BR>\n" );
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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;\">\r\n" );
document.write( "The variable \"y\" represents the current amount of the isotope NA-24 in the sample after x half-life periods.\r\n" );
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document.write( "The variable \"x\" represents the number of half-life periods after the beginning of the decay process.\r\n" );
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document.write( "For example, x = 2 means \"2 half-life periods\", i.e. 2*10 = 20 hours.\r\n" );
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document.write( "Answered and solved.\r<BR>\n" );
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document.write( "Notice that the formula in your post &nbsp;IS &nbsp;NOT &nbsp;traditional and &nbsp;DIFFERS &nbsp;from the traditional decay function/formula.\r<BR>\n" );
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document.write( "The traditional decay formula for this isotope would be   &nbsp;&nbsp;y = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=400%2A%281%2F2%29%5E%28t%2F10%29 ALIGN=MIDDLE  ALT=\"400%2A%281%2F2%29%5E%28t%2F10%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, &nbsp;where &nbsp;t &nbsp;is the time in hours.\r<BR>\n" );
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