document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=799820>Question 799820</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Verify that each equation is an identity\r<BR>\n" );
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document.write( "(2cos^2 (X/2)) (tan X) = tan X + sin X\r<BR>\n" );
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document.write( "1-tan^2 (t/2) = ((2cos t)/(1+cos t)) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #482915 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=482915\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Verify that each equation is an identity<BR>\n" );
document.write( "..<BR>\n" );
document.write( "(2cos^2 (X/2)) (tan X) = tan X + sin X<BR>\n" );
document.write( "Identity:cos(x/2)=&#8730;((1+cosx)/2)<BR>\n" );
document.write( "start with left side:<BR>\n" );
document.write( "2((1+cosx)/2)(tanx)=tanx+tanxcosx=tanx+(sinx/cosx)*cosx=tanx+sinx<BR>\n" );
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document.write( "..<BR>\n" );
document.write( "1-tan^2 (t/2) = ((2cos t)/(1+cos t))<BR>\n" );
document.write( "Identity: tan(t/2)=sint/(1+cost)<BR>\n" );
document.write( "start with left side:<BR>\n" );
document.write( "1-(sint/(1+cost))^2=1-(sin^2t)/(1+cost)^2<BR>\n" );
document.write( "=((1+cos^t)^2-sin^2t)/(1+cost)^2<BR>\n" );
document.write( "=(1+2cost+cos^2t-1+cos^2t)/(1+cost)^2<BR>\n" );
document.write( "=(2cost+2cos^2t)/(1+cost)^2<BR>\n" );
document.write( "=2cost(1+cost)/(1+cost)^2=2cost/(1+cost)<BR>\n" );
document.write( "verified: left side=right side<BR>\n" );
document.write( " </SPAN>\n" );
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