document.write( "Question 1063062: What is the exact value of sin(-7pi/12) and how do you find it? \n" ); document.write( "

Algebra.Com's Answer #678075 by ikleyn(52794) $\"\"$ $\"About$

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document.write( "Exact value of sin(-7pi/12) is\r\n" );
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document.write( " =  = \r\n" );
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document.write( "To find , use the formula of half argument for cosines \r\n" );
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document.write( "    (see the lesson  Trigonometric functions of half argument  in this site):\r\n" );
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document.write( "cos^2(15°) = (1+cos(30°)/2 =  = .\r\n" );
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document.write( "Hence,  \r\n" );
document.write( "cos(15°) = .\r\n" );
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document.write( "Thus   = .\r\n" );
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\n" ); document.write( "\n" ); document.write( "See the lesson \r
\n" ); document.write( "\n" ); document.write( " - Trigonometric functions of half argument - Examples\r
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\n" ); document.write( "\n" ); document.write( "Regarding the solution by the tutor \"math_helper\" for this problem, I want to notice that this solution consists and coincides with my:\r
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\n" ); document.write( "\n" ); document.write( " $\"%28+-+%28sqrt%282%29%2F4%29%281%2Bsqrt%283%29%29%29+\"$ = $\"-sqrt%282%2Bsqrt%283%29%29%2F2\"$ .\r
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\n" ); document.write( "\n" ); document.write( "Everybody who squares both sides can check it and convince himself or herself.\r
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