document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=912958>Question 912958</A>: <I><SPAN STYLE=\"word-break: break-all;\"> prove the identity:\r<BR>\n" );
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document.write( "a)<BR>\n" );
document.write( "cosh x - sinh x = e^-x\r<BR>\n" );
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document.write( "b)<BR>\n" );
document.write( "find the derivative<BR>\n" );
document.write( "f(t) = csch t(1- ln csch t) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #554206 by </B><A HREF=/tutors/aboutme.mpl?userid=ewatrrr><B>ewatrrr(24785)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ewatrrr><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=ewatrrr><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=554206\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <BR>\n" );
document.write( "re TY<BR>\n" );
document.write( "Yes, practice is good.<BR>\n" );
document.write( "Recommend carefully keeping things 'intact' until You go in 'for the finish\"<BR>\n" );
document.write( "a) <BR>\n" );
document.write( "coshx = (e^x + e^(-x))/2 <BR>\n" );
document.write( "-sinhx = <u>-(e^x - e^(-x))/2)</u><BR>\n" );
document.write( "cosh x - sinh x  = 2(e^(-x))/2) = e^(-x )<BR>\n" );
document.write( "............<BR>\n" );
document.write( "b)f(t) = csch t(1- ln csch t) <BR>\n" );
document.write( "f' = -csch(t)coth (t) - [-csch(t)coth (x)ln(csch(t) + csch(t)( -csch(t)coth (x)/csch(t)] <BR>\n" );
document.write( " -csch(t)coth (t) +csch(t)coth (x)ln(csch(t) + csch(t)coth (x) <BR>\n" );
document.write( " f' = csch(t)coth (t)ln(csch(t)  </SPAN>\n" );
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