document.write( "Question 373947: using the periodic properties of trigonometric functions find the exact value of the expression cos(8p/3)?
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Algebra.Com's Answer #266144 by Edwin McCravy(20060)\"\" \"About 
You can put this solution on YOUR website!
\"cos%288pi%2F3%29\"\r
\n" ); document.write( "\n" ); document.write( "\"cos%28expr%288%2F3%29pi%29\"\r
\n" ); document.write( "\n" ); document.write( "\"cos%28expr%282%262%2F3%29pi%29\"\r
\n" ); document.write( "\n" ); document.write( "\"cos%28%282%2B2%2F3%29pi%29\"\r
\n" ); document.write( "\n" ); document.write( "\"cos%282pi%2Bexpr%282%2F3%29pi%29%29\"\r
\n" ); document.write( "\n" ); document.write( "\"cos%28expr%282%2F3%29pi%2B2pi%29\"\r
\n" ); document.write( "\n" ); document.write( "By the fact that the period of cosine is \"2pi\", the above equals\r
\n" ); document.write( "\n" ); document.write( "\"cos%28+++expr%282%2F3%29pi++%29\"\r
\n" ); document.write( "\n" ); document.write( "and that's the same as \"2pi%2F3\" or 120°, a second quadrant
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\n" ); document.write( "\n" ); document.write( "\"-1%2F2\"\r
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