document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=519102>Question 519102</A>: <I><SPAN STYLE=\"word-break: break-all;\"> prove the following is an identity\r<BR>\n" );
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document.write( "sin(theta+60degrees) + cos(theta+30degrees)= sqr3costheta </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #345461 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=345461\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> prove the following is an identity <BR>\n" );
document.write( "sin(theta+60degrees) + cos(theta+30degrees)= sqr3costheta<BR>\n" );
document.write( "**<BR>\n" );
document.write( "x=theta<BR>\n" );
document.write( "sin(x+60)+cos(x+30)=&#8730;3cosx<BR>\n" );
document.write( "starting with left side, using addition formulas for sin and cos<BR>\n" );
document.write( "sin(x+60)=sinxcos60+cosxsin60<BR>\n" );
document.write( "=sinx/2+&#8730;3cosx/2<BR>\n" );
document.write( "..<BR>\n" );
document.write( "cos(x+30)=cosxcos30-sinxsin30<BR>\n" );
document.write( "=cosx&#8730;3/2-sinx/2<BR>\n" );
document.write( "..<BR>\n" );
document.write( "sin(x+60)+cos(x+30)<BR>\n" );
document.write( "=sinx/2+&#8730;3cosx/2+cosx&#8730;3/2-sinx/2<BR>\n" );
document.write( "=&#8730;3cosx<BR>\n" );
document.write( "verified: left side=right side </SPAN>\n" );
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