document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=230798>Question 230798</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Hi,<BR>\n" );
document.write( "I have a \"Trig Identity\" problem that I'm to verify. I know they are equal by substituting in a value, but I don't know how to approach it. I thought using a conjugate was the way, but it got me nowhere. Here is the problem:\r<BR>\n" );
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document.write( "(cotX * cosX)/(cotX + cosX) = (cotX - cosX)/(cotX * cosX)\r<BR>\n" );
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document.write( "Thank you,<BR>\n" );
document.write( "Lynn </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #170933 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=170933\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> (cotX * cosX)/(cotX + cosX) = (cotX - cosX)/(cotX * cosX) <BR>\n" );
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document.write( "Since it's all x I'll leave it out.<BR>\n" );
document.write( "Cross multiply<BR>\n" );
document.write( "(cot*cos)^2 = cot^2 - cos^2<BR>\n" );
document.write( "(cos^2/sin^2)*cos^2 = (cos^2/sin^2) - cos^2<BR>\n" );
document.write( "Divide out cos^2<BR>\n" );
document.write( "cos^2/sin^2 = (1/sin^2) - 1 <BR>\n" );
document.write( "cos^2/sin^2 = (1 - sin^2)/sin^2 <BR>\n" );
document.write( "cos^2/sin^2 = cos^2/sin^2<BR>\n" );
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document.write( "PS  If you sub a value and it doesn't work, you know it's not an identity.  <BR>\n" );
document.write( "If a value does work, that doesn't guarantee it works for all values.<BR>\n" );
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