document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=665365>Question 665365</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Assume that sin x= 0.8 and sin y= square root of 0.75. find cos (x+y) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #414046 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=414046\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Assume that sin x= 0.8 and sin y= square root of 0.75. find cos (x+y)<BR>\n" );
document.write( "**<BR>\n" );
document.write( "Identity: cos(x+y)=cosxcosy-sinxsiny<BR>\n" );
document.write( "..<BR>\n" );
document.write( "sinx=0.8=8/10=4/5 (3-4-5 right triangle)<BR>\n" );
document.write( "cosx=3/5<BR>\n" );
document.write( "siny=&#8730;.75=&#8730;3/4=&#8730;3/2<BR>\n" );
document.write( "y=&#960;/3<BR>\n" );
document.write( "cosy=1/2<BR>\n" );
document.write( "..<BR>\n" );
document.write( "cos(x+y)=cosxcosy-sinxsiny<BR>\n" );
document.write( "=3/5*1/2-4/5*&#8730;3/2<BR>\n" );
document.write( "=3/10-4&#8730;3/10<BR>\n" );
document.write( "=(3-4&#8730;3)/10\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );