document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=919115>Question 919115</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Verify the identity. \r<BR>\n" );
document.write( "\n" );
document.write( "cot(x-(pi/2))=-tan(x) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #557548 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=557548\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Verify the identity.<BR>\n" );
document.write( "cot(x-(pi/2))=-tan(x)<BR>\n" );
document.write( "***<BR>\n" );
document.write( "start with left side:<BR>\n" );
document.write( "cot(x-&#960;/2)=cos(x-&#960;/2)/sin(x-&#960;/2)<BR>\n" );
document.write( "cos(x-&#960;/2)=cosxcos(&#960;/2)+sinxsin(&#960;/2)=cosx*0+sinx*1=0+sinx=sinx<BR>\n" );
document.write( "sin(x-&#960;/2)=sinxcos(&#960;/2)-cosxsin(&#960;/2)=sinx*0-cosx*1=0-cosx=-cosx<BR>\n" );
document.write( "cot(x-&#960;/2)=cos(x-&#960;/2)/sin(x-&#960;/2)=sinx/-cosx=-tanx<BR>\n" );
document.write( "verified: left side=right side </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );