document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=81133>Question 81133</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Assume that the number of viruses present in a sample is modeled by the exponential function \"f(t) = 10t\", where t is the elapsed time in minutes. How would you apply logarithms to determine when the sample will grow to 5 billion viruses? <BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #58153 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=58153\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Assume that the number of viruses present in a sample is modeled by the exponential function \"f(t) = 10t\", where t is the elapsed time in minutes. How would you apply logarithms to determine when the sample will grow to 5 billion viruses? <BR>\n" );
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document.write( "f(t) = 10^t<BR>\n" );
document.write( "5x10^9 = 10^t<BR>\n" );
document.write( "Take the log of both sides to get:<BR>\n" );
document.write( "log5 + log10^9 = t<BR>\n" );
document.write( "log5 + 9 = t<BR>\n" );
document.write( "t = 9.6989... minutes<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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