document.write( "Question 842702: Let sin s=-2/3, with s in quad. 3 and let cos t=-1/3, with t in quad. 2. Find each of the following.\r
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Algebra.Com's Answer #507782 by lwsshak3(11628)\"\" \"About 
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Let sin s=-2/3, with s in quad. 3 and let cos t=-1/3, with t in quad. 2. Find each of the following.
\n" ); document.write( "Sin(s+t)
\n" ); document.write( "Identity: sin(s+t)=sin(s)cos(t)+cos(s)sin(t)
\n" ); document.write( "sin(s)=-2/3
\n" ); document.write( "cos(s)=-√(1-sin^2(s))=-√(1-4/9)=-√(5/9)=-√5/3
\n" ); document.write( "cos(t)=-1/3
\n" ); document.write( "sin(t)=√(1-cos^2(t))=√(1-1/9)=√(8/9)=√8/3
\n" ); document.write( "sin(s+t)=-2/3*-1/3+-√5/3*√8/3
\n" ); document.write( "=2/9-√40/9
\n" ); document.write( "=(2-√40)/9
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\n" ); document.write( "Calculator check:
\n" ); document.write( "sin(s)=-2/3
\n" ); document.write( "s≈221.81˚
\n" ); document.write( "cos(t)=-1/3)
\n" ); document.write( "t≈109.47˚
\n" ); document.write( "s+t≈331.28
\n" ); document.write( "sin(s+t)=sin(331.38)≈-0.4790
\n" ); document.write( "exact value as calculated=(2-√40)/9≈-0.4805 \n" ); document.write( "
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