document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=873143>Question 873143</A>: <I><SPAN STYLE=\"word-break: break-all;\"> if sin alpha =2/3 for pi/2&#8804;alpha&#8804;pi and cos beta =-5/7 for pi&#8804;beta&#8804;3pi/2, find the value of cos(alpha+beta) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #526950 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=526950\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> if sin alpha =2/3 for pi/2&#8804;alpha&#8804;pi and cos beta =-5/7 for pi&#8804;beta&#8804;3pi/2, find the value of cos(alpha+beta)<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sin%28alpha%29=2%2F3 ALIGN=MIDDLE  ALT=\"sin%28alpha%29=2%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" > (in quadrant II in which sin>0, cos<0)<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%28alpha%29=-sqrt%281-sin%5E2%28alpha%29%29=-sqrt%281-%284%2F9%29%29=-sqrt%285%2F9%29=-sqrt%285%29%2F3%29 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "..<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%28beta%29=-5%2F7 ALIGN=MIDDLE  ALT=\"cos%28beta%29=-5%2F7\"   DISABLED_style= \"max-width:90%; height:auto;\" > (in quadrant III in which sin<0, cos<0)<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sin%28beta%29=-sqrt%281-cos%5E2%28beta%29%29=-sqrt%281-%2825%2F49%29%29=-sqrt%2824%2F49%29=-sqrt%2824%29%2F7%29 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "..<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%28alpha%29%2B%28beta%29=cos%28alpha%29%2Acos%28beta%29-sin%28alpha%29%2Asin%28beta%29 ALIGN=MIDDLE  ALT=\"cos%28alpha%29%2B%28beta%29=cos%28alpha%29%2Acos%28beta%29-sin%28alpha%29%2Asin%28beta%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%28alpha%29%2B%28beta%29=-%28sqrt%285%29%2F3%29%2A%28-5%2F7%29-%282%2F3%29%2A%28-sqrt%2824%29%2F7%29=5sqrt%285%29%2F21%2B2sqrt%2824%29%2F21=%285sqrt%285%29%2B2sqrt%2824%29%29%2F21 ALIGN=MIDDLE   DISABLED_style= \"max-width:90%; height:auto;\" > </SPAN>\n" );
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