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Definition of Similarity Using Linear Transformations | Mathematics Prelims
https://mathprelims.wordpress.com/2009/06/25/definition-of-similarity-using-linear-transformations
June 25, 2009. Definition of Similarity Using Linear Transformations. 8212; cjohnson @ 12:24 pm. Let’s suppose we have a linear transformation. Which performs the following:. Now, the matrix representation of this transformation with respect to the standard basis is clearly. But suppose we were to use a different basis for. We see that our transformation maps these basis vectors as follows:. Looks like with respect to the. Basis, so let’s convert the vectors on the right to. So with respect to our. Note ...
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Determinants | Mathematics Prelims
https://mathprelims.wordpress.com/2009/06/13/determinants
June 13, 2009. 8212; cjohnson @ 9:10 pm. I remember that when I took linear algebra, I had learned determinants in a very “algorithmic” sort of way; a determinant to me was a function defined on square matrices by a particular recursive procedure. In Charles Cullen’s. Matrices and Linear Transformations. However, he defines a determinant not by a rule, but by two properties which completely characterize the determinant. A determinant, according to Cullen, is an. Function which satisfies the following.
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Eigenvalues and Eigenvectors | Mathematics Prelims
https://mathprelims.wordpress.com/2009/06/25/eigenvalues-and-eigenvectors
June 25, 2009. 8212; cjohnson @ 2:39 pm. Let’s suppose that. Matrix which is similar to a diagonal matrix,. This means there is an invertible (change-of-basis) matrix. Is a change of basis matrix, each of its columns gives the coordinates to a basis vector of some basis. Let’s call that basis. Be the elements of that basis. Now, if we take the above equation and multiply by. On the right, notice that. That is, the. Is equal to the. Since each column of. Is just a linear combination of the columns of.
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Linear Transformations and Matrix Representations | Mathematics Prelims
https://mathprelims.wordpress.com/2009/06/18/linear-transformations-and-matrix-representations
June 18, 2009. Linear Transformations and Matrix Representations. 8212; cjohnson @ 2:22 pm. Are vector spaces over the field. Is called a linear transformation if for all scalars. And for all vectors. Note that because of this linearity, a linear transformation is completely determined by how it maps the basis vectors of the domain. Suppose that. Is a basis for V. Let. Be any vector in. So if we know each. We can figure out where any other vector will be sent by. This does not mean that. It could be that.
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Determinants Are Linear in Rows and Columns | Mathematics Prelims
https://mathprelims.wordpress.com/2009/06/16/determinants-are-linear-in-rows-and-columns
June 16, 2009. Determinants Are Linear in Rows and Columns. 8212; cjohnson @ 8:55 pm. One easy consequence of our definition of determinant. From last time is that any singular matrix must have determinant zero. Suppose. Is the matrix which puts. Into row reduced form. Then we have. Is singular, once we put it in row reduced form it must have a row of zeros. We can now break. Up into a product of elementary matrices, one of which will have be of the form. Suppose now that the first row of. 8212; June 17,...
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Mathematics Prelims | Studying math. | Page 2
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June 11, 2009. 8212; cjohnson @ 10:02 pm. In the last post we defined the column and row space of a matrix as the span of the columns (in the case of the column space) or rows (for the row space) of the matrix. There’s a third important subspace of a matrix, called the. Which is the set of all vectors which. Maps to zero. That is, if we think of an. As a function from. Then the null space of. Is simply the kernel of the map. The dimension of the null space is sometimes called the. We begin by assuming.
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Change of Basis | Mathematics Prelims
https://mathprelims.wordpress.com/2009/06/13/change-of-basis
June 13, 2009. 8212; cjohnson @ 4:19 pm. In any non-trivial vector space there will be several possible bases we could pick. In. For instance, we could use. This first basis is known as the. And in general for an. Dimensional vector space over. We’ll refer to. As the standard basis, and will let. Denote the vector with a 1 in the. Th position, and zeros elsewhere. When we write down a vector like. Basis vectors by to get describe our vector. Let’s suppose our coefficients are. To mean that the. Is to con...
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The Laplace/Cofactor Expansion | Mathematics Prelims
https://mathprelims.wordpress.com/2009/06/17/the-laplacecofactor-expansion
June 17, 2009. 8212; cjohnson @ 3:22 pm. We’ve yet to describe a way to calculate determinants in any easy way; we’ve seen some nice properties, but still have to resort to writing a non-elementary matrix as a product of elementary matrices in order to calculate its determinant. What we want to do now is describe a recursive procedure for calculating a determinant by looking at determinants of submatrices. Let’s first agree to call the submatrix of. Th column deleted the. Which we’ll denote. Th column to...
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Every Vector Space Has a Basis | Mathematics Prelims
https://mathprelims.wordpress.com/2009/06/10/every-vector-space-has-a-basis
June 10, 2009. Every Vector Space Has a Basis. 8212; cjohnson @ 8:12 pm. This proof is adopted from the one that appears in an appendix to Larry Grove’s. Recall that Zorn’s lemma says that in a partially ordered set in which every chain has an upper bound, there exists a maximal element. We will use this to show that there must be a maximal linearly independent subset in a vector space, and argue that this set is a basis. Be any vector space and define the set. Be any chain in. Are in the chain with.