document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=735099>Question 735099</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If f(x)= cos(2x)-3sin(4x), find the exact value of f'(PIE/6) \r<BR>\n" );
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document.write( "The first step I thought of was cos(2A)= 1-Sin^2A because you'll need to make the cos into sin for the equation to work. Thanks. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #449449 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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=449449\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> If f(x)= cos(2x)-3sin(4x), find the exact value of f'(PIE/6)<BR>\n" );
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document.write( "For[0,2&#960;]<BR>\n" );
document.write( "f(x)= cos(2x)-3sin(4x)<BR>\n" );
document.write( "f(&#960;/6)=cos(2&#960;/6)-3sin(4&#960;/6)<BR>\n" );
document.write( "..<BR>\n" );
document.write( "cos(2&#960;/6)=cos(&#960;/3)=1/2<BR>\n" );
document.write( "sin(4&#960;/6)=sin(2&#960;/3)=&#8730;3/2 (in Q2 where sin>0)<BR>\n" );
document.write( "..<BR>\n" );
document.write( "f(&#960;/6)=cos(2&#960;/6)-3sin(4&#960;/6)<BR>\n" );
document.write( "=cos(&#960;/3)-3sin(2&#960;/3)<BR>\n" );
document.write( "=1/2-3&#8730;3/2<BR>\n" );
document.write( "=(1-3&#8730;3)/2 </SPAN>\n" );
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