document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=167728>Question 167728</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Verify this identity :\r<BR>\n" );
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document.write( "(tan^2(x)-1)/(1+tan^2(x)) = 1-2cos^2(x)\r<BR>\n" );
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document.write( "I've started a couple different options but none are working out for me. Here is what I have so far :\r<BR>\n" );
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document.write( "A)<BR>\n" );
document.write( "multiply top by (1 + tan^2(x)) to get :<BR>\n" );
document.write( "tan^4 (x) -1 or (tan^2(x)+1)(tan^2x-1) <BR>\n" );
document.write( "then i'm stuck!\r<BR>\n" );
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document.write( "B) (tanx +1)(tanx-1)/1 + tan^2(x) =<BR>\n" );
document.write( "(sinx/cosx + 1)(sinx/cosx - 1) / 1/cosx<BR>\n" );
document.write( "then again I'm stuck!\r<BR>\n" );
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document.write( "I'm not sure if I should be working on the right side of the equation instead!  Grrrrr....I could get a little help from the tutors in the Math Lab on campus but we've been instructed not to seek them out for this problem (and another I am stuck on!).  Any tips would be helpful and thank you in advance for your time!!\r<BR>\n" );
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document.write( "Desperately seeking solution, Rebecca<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #676989 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=676989\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Verify this identity : <BR>\n" );
document.write( "(tan^2(x)-1)/(1+tan^2(x)) = 1-2cos^2(x) <BR>\n" );
document.write( "Verify this identity : <BR>\n" );
document.write( "(tan^2(x)-1)/sec^2 = 1-2cos^2(x) <BR>\n" );
document.write( "Mulitiply by cos^2<BR>\n" );
document.write( "(sin^2 - cos^2)/1 = 1 - 2cos^2<BR>\n" );
document.write( "Add cos^2<BR>\n" );
document.write( "sin^2 = 1 - cos^2<BR>\n" );
document.write( "QED<BR>\n" );
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