document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=46861>Question 46861</A>: <I><SPAN STYLE=\"word-break: break-all;\"> i was just wondering how you would write an equation that models the amplitude of the weight A(n) as a function of number of 20-swing periods n\r<BR>\n" );
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document.write( "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 #31039 by </B><A HREF=/tutors/aboutme.mpl?userid=adamchapman><B>adamchapman(301)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=adamchapman><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=31039\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> There si not a lot of information in your question, but I assume it is a bit like another problem i solved recently:<BR>\n" );
document.write( "\"A pendulum bob swings through an arc 70 inches long on its first swing. Each swing, thereafter, it swings only 89% as far as on the previous swing. What is the length of the arc after 9 swings?\"\r<BR>\n" );
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document.write( "The length of the nth swing is 0.89 times the length of the (n-1)th swing.<BR>\n" );
document.write( "Let the length of the nth swing be <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=L%5Bn%5D ALIGN=MIDDLE  ALT=\"L%5Bn%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=L%5B1%5D=70 ALIGN=MIDDLE  ALT=\"L%5B1%5D=70\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=L%5B2%5D=0.89%2870%29 ALIGN=MIDDLE  ALT=\"L%5B2%5D=0.89%2870%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=L%5B3%5D=0.89%280.89%2870%29%29=0.89%5E2%2870%29 ALIGN=MIDDLE  ALT=\"L%5B3%5D=0.89%280.89%2870%29%29=0.89%5E2%2870%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=L%5B4%5D=0.89%280.89%280.89%2870%29%29%29=0.89%5E3%2870%29 ALIGN=MIDDLE  ALT=\"L%5B4%5D=0.89%280.89%280.89%2870%29%29%29=0.89%5E3%2870%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "See a pattern emerging yet?<BR>\n" );
document.write( "The formula for the length of the nth swing is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=L%5Bn%5D=70%280.89%5E%28%28n-1%29%29%29 ALIGN=MIDDLE  ALT=\"L%5Bn%5D=70%280.89%5E%28%28n-1%29%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "So The length of the 9th swing is......<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=L%5B9%5D=70%280.89%5E8%29 ALIGN=MIDDLE  ALT=\"L%5B9%5D=70%280.89%5E8%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "which is 27.56 inches, to 2 decimal places.\r<BR>\n" );
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document.write( "I hope this helps,<BR>\n" );
document.write( "Adam<BR>\n" );
document.write( "P.S. please visit my website, it may be helpful to you. The address is www.geocities.com/quibowibbler<BR>\n" );
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