document.write( "Question 769452: Find the exact value by using a half-angle identity.
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Algebra.Com's Answer #469034 by tommyt3rd(5050)\"\" \"About 
You can put this solution on YOUR website!
cosine is an even function so\r
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\n" ); document.write( "\n" ); document.write( "\"cos%28%28pi%2F4%29%2F2%29=sqrt%28%281%2Bcos%28pi%2F4%29%29%2F2%29\"\r
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