document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=136165>Question 136165</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 1. Arsenic-74 is used to locate brain tumors. It has a half-life of 17.5 days. Write an exponential decay function for a 90-mg sample. Use the function to find the amount remaining after 6 days?<BR>\n" );
document.write( "PLEASE HELP ME. (sorry for caps im not shouting it just I've been having trouble and no has been helping me)-thank you </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #99750 by </B><A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><B>jim_thompson5910(35256)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jim_thompson5910><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=99750\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The formula for a half-life function is \r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A%5Br%5D=A%5B0%5D%281%2F2%29%5E%28t%2FH%29 ALIGN=MIDDLE  ALT=\"A%5Br%5D=A%5B0%5D%281%2F2%29%5E%28t%2FH%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > where <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A%5Br%5D ALIGN=MIDDLE  ALT=\"A%5Br%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" > is the amount remaining, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A%5B0%5D ALIGN=MIDDLE  ALT=\"A%5B0%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" > is the original amount of the substance, and H is the half-life\r<BR>\n" );
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document.write( "So in our case A=90 and H=17.5\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A%5Br%5D=90%281%2F2%29%5E%28t%2F17.5%29 ALIGN=MIDDLE  ALT=\"A%5Br%5D=90%281%2F2%29%5E%28t%2F17.5%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > Plug in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A%5B0%5D=90 ALIGN=MIDDLE  ALT=\"A%5B0%5D=90\"   DISABLED_style= \"max-width:90%; height:auto;\" > and H=17.5\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A%5Br%5D=90%281%2F2%29%5E%286%2F17.5%29 ALIGN=MIDDLE  ALT=\"A%5Br%5D=90%281%2F2%29%5E%286%2F17.5%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >  Since we want to know how much is remaining after 6 days, simply plug in <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t=6 ALIGN=MIDDLE  ALT=\"t=6\"   DISABLED_style= \"max-width:90%; height:auto;\" > \r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A%5Br%5D=90%281%2F2%29%5E%280.34286%29 ALIGN=MIDDLE  ALT=\"A%5Br%5D=90%281%2F2%29%5E%280.34286%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > Divide\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A%5Br%5D=90%280.78847%29 ALIGN=MIDDLE  ALT=\"A%5Br%5D=90%280.78847%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > Raise <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=1%2F2 ALIGN=MIDDLE  ALT=\"1%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" > to the 0.34286th power to get 0.78847\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=A%5Br%5D=70.9623 ALIGN=MIDDLE  ALT=\"A%5Br%5D=70.9623\"   DISABLED_style= \"max-width:90%; height:auto;\" > Multiply \r<BR>\n" );
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document.write( "So in 6 days, there will be about 70.9623 mg of arsenic left over </SPAN>\n" );
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