document.write( "Question 1008347: Find the exact value for sin(alpha-beta) if sin(alpha) = -5/13 and cos(beta) = -8/17 with alpha in quadrant 3 and beta in quadrant 2 \n" ); document.write( "

Algebra.Com's Answer #624084 by ikleyn(52794) $\"\"$ $\"About$

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\n" ); document.write( "Find the exact value for sin(alpha-beta) if sin(alpha)=-5/13 and cos(beta)=-8/17 with alpha in quadrant 3 and beta in quadrant 2
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document.write( "If  = , then  = - = - = - = - = -   \r\n" );
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document.write( "             (the sign is \"minus\" because  is in quadrant 3).\r\n" );
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document.write( "If  = , then  =  =  =  =  =    \r\n" );
document.write( "          \r\n" );
document.write( "             (the sign is \"plus\" because  is in quadrant 2).\r\n" );
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document.write( "Now use the formula sin(alpha-beta) = sin(alpha)*cos(beta)-cos(alpha)*sin(beta).\r\n" );
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document.write( "             It is a fundamental formula Trigonometry. If you don't know it, you may look into \r\n" );
document.write( "             the lesson Addition and subtraction formulas in this site.\r\n" );
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document.write( "Now substitute the given and the found values of cos and sin into this formula. You will get \r\n" );
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document.write( " = . - .. \r\n" );
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document.write( "At this point I will leave you. Please complete calculations yourself. \r\n" );
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