document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=991918>Question 991918</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I need help with this: Find the value of k for which <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y+=+1%2Fk ALIGN=MIDDLE  ALT=\"y+=+1%2Fk\"   DISABLED_style= \"max-width:90%; height:auto;\" > sin k x has a period of <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=4pi ALIGN=MIDDLE  ALT=\"4pi\"   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #611637 by </B><A HREF=/tutors/aboutme.mpl?userid=Theo><B>Theo(13342)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Theo><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=Theo><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=611637\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> i believe your answer is that k = 1/2.\r<BR>\n" );
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document.write( "here's why.\r<BR>\n" );
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document.write( "the equation is y = 1/k * sin(kx)\r<BR>\n" );
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document.write( "k is the frequency.\r<BR>\n" );
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document.write( "the period is equal to 2pi / frequency.\r<BR>\n" );
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document.write( "the period is 4pi.\r<BR>\n" );
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document.write( "you get 4pi = 2pi / k\r<BR>\n" );
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document.write( "solve for k to get k = 2pi / 4pi which is equal to 1/2.\r<BR>\n" );
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document.write( "a wrinkle in this problem is that k is also involved in the amplitude.\r<BR>\n" );
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document.write( "disregard that for purposes of solving the problem since the frequency and the period are you main interests.\r<BR>\n" );
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document.write( "your equation becomes y = 1/(1/2) * sin (1/2 * x).\r<BR>\n" );
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document.write( "the graph of that equation is shown below:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" src = \"http://theo.x10hosting.com/2015/092407.jpg\" alt=\"$$$\" </>\r<BR>\n" );
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document.write( "note that the amplitude is 2.\r<BR>\n" );
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document.write( "normally it is 1, but 1/(1/2) is equal to 2.\r<BR>\n" );
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document.write( "the k affected the amplitude as well as the period.\r<BR>\n" );
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