document.write( "Question 1181163: If 1 and w are 2 of the 5 roots of (w)^5 = 1, then prove the following:\r
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\n" ); document.write( "\n" ); document.write( "b) 1 + w + (w)^2 + (w)^3 + (w)^4 = 0\r
\n" ); document.write( "\n" ); document.write( "c) (w)^(5n) = 1 for any integer n
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Algebra.Com's Answer #811039 by Edwin McCravy(20055)\"\" \"About 
You can put this solution on YOUR website!
If 1 and w are 2 of the 5 roots of (w)^5 = 1, then prove the following:
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document.write( "where cis(θ) = cos(θ)+isin(θ),\r\n" );
document.write( "The 5 fifth roots of 1 are \r\n" );
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document.write( "\"%28cis%2872%5Eo%29%5E%22%22%29%5E2=cis%282%2A72%5Eo%29=cis%28144%5Eo%29\"\r\n" );
document.write( "\"%28cis%28144%5Eo%29%5E%22%22%29%5E2=cis%282%2A144%5Eo%29=cis%28288%5Eo%29\"\r\n" );
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document.write( "\"%28cis%2872%5Eo%29%5E%22%22%29%5E3=cis%283%2A72%5Eo%29=cis%28216%5Eo%29\"\r\n" );
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document.write( "\"%28cis%2872%5Eo%29%5E%22%22%29%5E4=cis%284%2A72%5Eo%29=cis%28288%5Eo%29\"\r\n" );
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b) 1 + w + (w)^2 + (w)^3 + (w)^4 = 0, provided w ≠ 1
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document.write( "\"w%5E5=1\"\r\n" );
document.write( "\"w%5E5-1=0\"\r\n" );
document.write( "\"%28w-1%29%28w%5E4%2Bw%5E3%2Bw%5E2%2Bw%2B1%29=0\"\r\n" );
document.write( "Since w ≠ 1, w-1 ≠ 0, so\r\n" );
document.write( "\"w%5E4%2Bw%5E3%2Bw%5E2%2Bw%2B1+=+0\"\r\n" );
document.write( "\"1%2Bw%2Bw%5E2%2Bw%5E3%2Bw%5E4=0\"\r\n" );
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c) (w)^5n = 1 for any integer n
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document.write( "\"w%5E5+=+1\"\r\n" );
document.write( "Raise both sides to the 5th power:\r\n" );
document.write( "\"%28w%5E5%29%5En=1%5En\"\r\n" );
document.write( "\"w%5E%285n%29=1\"\r\n" );
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document.write( "Edwin
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