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Math Help - units of polynomial(ring theory)

  1. #1
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    units of polynomial(ring theory)

    Prove that if char(R) = n then char(R[x]) = n.
    Last edited by CarmineCortez; November 26th 2009 at 09:15 AM.
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  2. #2
    Senior Member Shanks's Avatar
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    Since R[x] contains R, so charR[x] is no less than charR.
    If char R is infinite,then it is trivial.
    otherwise,Let charR = n, suppose f be any element in R[x], then all the coefficients of nf are 0, since charR=n. So charR[x] is no greater than charR.
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