document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=544713>Question 544713</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the exact values using double angle formulas:\r<BR>\n" );
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document.write( "a) cos 112.5 degrees<BR>\n" );
document.write( "b) tan 22.5 degrees </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #355510 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=355510\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Find the exact values using double angle formulas: <BR>\n" );
document.write( "a) cos 112.5 degrees<BR>\n" );
document.write( "b) tan 22.5 degrees<BR>\n" );
document.write( "**<BR>\n" );
document.write( "I think you meant using half-angle formulas:<BR>\n" );
document.write( "..<BR>\n" );
document.write( "a) cos 112.5º= cos (225/2)º=-&#8730;[(1+cos 225º)/2)]<BR>\n" );
document.write( "1+cos 225º=1-&#8730;2/2=(2-&#8730;2)/2<BR>\n" );
document.write( "(1+cos 225º)/2)=(2-&#8730;2)/4<BR>\n" );
document.write( "-&#8730;[(1+cos 225º)/2)]=-&#8730;(2-&#8730;2)/2<BR>\n" );
document.write( "cos 112.5º=-&#8730;(2-&#8730;2)/2<BR>\n" );
document.write( "..<BR>\n" );
document.write( "b) tan22.5º=tan (45/2)º=(sin 45º)/(1+cos 45º)=&#8730;2/2/(1+&#8730;2/2)<BR>\n" );
document.write( "tan 22.5º=&#8730;2/(2+&#8730;2) </SPAN>\n" );
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