Proving Vector Space Dimensionality of F[x]/(g(x))

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SUMMARY

F[x]/(g(x)) is confirmed as an n-dimensional vector space where g is a polynomial of degree n in F[x]. The basis B = (1, x, x^2, ..., x^(n-1)) spans this vector space. To demonstrate that B is linearly independent, one must construct a matrix with B as the first row and its successive derivatives as subsequent rows. Evaluating the determinant of this matrix will establish the linear independence of B, regardless of the characteristic of the field F.

PREREQUISITES
  • Understanding of vector spaces and their properties
  • Familiarity with polynomial rings, specifically F[x]
  • Knowledge of matrix determinants and linear independence
  • Concept of derivatives in the context of polynomial functions
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  • Learn about polynomial rings and their ideals in abstract algebra
  • Explore the computation of determinants and their implications for linear independence
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Mathematics students, particularly those studying abstract algebra and linear algebra, as well as educators seeking to deepen their understanding of vector spaces and polynomial structures.

johnson123
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Homework Statement



Show that F[x]/( g(x) ) is a n-dimensional vector space. where g is in F[x],
and g has degree n.

Its clear that F[x]/( g(x) ) is a vector space and that

B= (1,x^{2},...,x^{n-1}) spans F[x]/( g(x) ),

but I am having trouble showing that B is linearly independent
 
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Write a matrix whose first row is B=(1,x,x^2...x^(n-1)), whose second row is the first derivative of the first, whose third row is the second derivative of the first etc. If B were linearly independent, then the columns of the matrix would be linearly dependent, so the determinant would be zero. Now evaluate the determinant. You may have to do some extra head scratching if the characteristic of your field isn't zero.
 
It shouldn't matter what the characteristic of the field is. Just write down a relation among the x^k with coefficients from F. If this is 0 in F[x] / g(x), then it means that it lives in the ideal g(x), i.e., is a polynomial times g(x). I leave the rest to you.
 

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