document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1170381>Question 1170381</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Which expression is equivalent to sin(0.6x)-sin(0.4x)?\r<BR>\n" );
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document.write( "a. 2cos(0.5x)sin(0.1x)<BR>\n" );
document.write( "b. 2cos(0.5x)cos(0.1x)<BR>\n" );
document.write( "c. 2sin(0.5x)sin(0.1x)<BR>\n" );
document.write( "d.-2sin(0.5x)sin(0.1x)<BR>\n" );
document.write( "e.-2cos(0.5x)sin(0.1x) <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 #795271 by </B><A HREF=/tutors/aboutme.mpl?userid=MathLover1><B>MathLover1(20850)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=MathLover1><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=MathLover1><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=795271\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> \r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sin%280.6x%29-sin%280.4x%29 ALIGN=MIDDLE  ALT=\"sin%280.6x%29-sin%280.4x%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=u=0.1x ALIGN=MIDDLE  ALT=\"u=0.1x\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "then we have\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sin%286u%29-sin%284u%29 ALIGN=MIDDLE  ALT=\"sin%286u%29-sin%284u%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "use the following identity : <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sin%28s+%29-+sin%28t+%29=2cos%28%28s%2Bt%29%2F2%29sin%28%28s-t%29%2F2%29+ ALIGN=MIDDLE  ALT=\"sin%28s+%29-+sin%28t+%29=2cos%28%28s%2Bt%29%2F2%29sin%28%28s-t%29%2F2%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" >where <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=s=6u ALIGN=MIDDLE  ALT=\"s=6u\"   DISABLED_style= \"max-width:90%; height:auto;\" > and<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t=4u ALIGN=MIDDLE  ALT=\"+t=4u\"   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=sin%286u+%29-+sin%284u+%29=2cos%28%286u%2B4u%29%2F2%29sin%28%286u-4u%29%2F2%29 ALIGN=MIDDLE  ALT=\"sin%286u+%29-+sin%284u+%29=2cos%28%286u%2B4u%29%2F2%29sin%28%286u-4u%29%2F2%29\"   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=sin%286u+%29-+sin%284u+%29=2cos%2810u%2F2%29sin%282u%2F2%29 ALIGN=MIDDLE  ALT=\"sin%286u+%29-+sin%284u+%29=2cos%2810u%2F2%29sin%282u%2F2%29\"   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=sin%286u+%29-+sin%284u+%29=2cos%285u%29sin%28u%29 ALIGN=MIDDLE  ALT=\"sin%286u+%29-+sin%284u+%29=2cos%285u%29sin%28u%29\"   DISABLED_style= \"max-width:90%; height:auto;\" > ............since <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=u=0.1x ALIGN=MIDDLE  ALT=\"u=0.1x\"   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=sin%286%2A0.1x+%29-+sin%284%2A0.1x+%29=2cos%285%2A0.1x%29sin%280.1x%29 ALIGN=MIDDLE  ALT=\"sin%286%2A0.1x+%29-+sin%284%2A0.1x+%29=2cos%285%2A0.1x%29sin%280.1x%29\"   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=sin%280.6x+%29-+sin%280.4x+%29=2cos%280.5x%29sin%280.1x%29 ALIGN=MIDDLE  ALT=\"sin%280.6x+%29-+sin%280.4x+%29=2cos%280.5x%29sin%280.1x%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "so, answer is\r<BR>\n" );
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document.write( "a. <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=2cos%280.5x%29sin%280.1x%29 ALIGN=MIDDLE  ALT=\"2cos%280.5x%29sin%280.1x%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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