document.write( "Question 981306: Find the exact value of sin 225 degrees. You must use a sum or difference formula for your solution to be graded \n" ); document.write( "
Algebra.Com's Answer #602327 by MathLover1(20850)\"\" \"About 
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first write \"sin+%28225%29\" as \"sin+%28180%2B45+%29+\"\r
\n" ); document.write( "\n" ); document.write( "then we have \"sin%28180%2B45%29\"\r
\n" ); document.write( "\n" ); document.write( "use a sum formula\r
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\n" ); document.write( "\n" ); document.write( "\"sin%28180%2B45%29+=+sin%28180%29cos%2845%29+%2B+cos%28180%29sin%2845%29\"....since \"sin%28180%29=0\",\"sin%2845%29=1%2Fsqrt%282%29\",\"cos%2845%29=1%2Fsqrt%282%29\", and \"cos%28180%29=-1\", we have \r
\n" ); document.write( "\n" ); document.write( "\"sin%28180%2B45+%29+=+0%2A%281%2Fsqrt%282%29%29+%2B%28-1%29%281%2Fsqrt%282%29%29\"\r
\n" ); document.write( "\n" ); document.write( "\"sin%28180%2B45+%29+=+-1%2Fsqrt%282%29\"
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