document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=211679>Question 211679</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please, I need your help to find the exact value of the following without using a calculator:\r<BR>\n" );
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document.write( "(sin^2)(225degrees)-(cos^2)(300degrees) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #159956 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=159956\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> find the exact value of the following without using a calculator: <BR>\n" );
document.write( "(sin^2)(225degrees)-(cos^2)(300degrees)<BR>\n" );
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document.write( "The reference angle for 225 degrees is 45 degrees in the 3rd quadrant<BR>\n" );
document.write( "sin(225) = -sin(45) = (sqrt(2))/2<BR>\n" );
document.write( "So, sin^2(225) = 2/4 = 1/2<BR>\n" );
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document.write( "The reference angle for 300 degrees is 60 degrees in the 4th quadrant.<BR>\n" );
document.write( "cos(300) = cos(60) = 1/2<BR>\n" );
document.write( "So, cos^2(300) = (1/2)^2 = 1/4<BR>\n" );
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document.write( "Ans: 1/2 - 1/4 = 1/4<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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