Matrix theory

Nullity theorem

The nullity theorem is a mathematical theorem about the inverse of a partitioned matrix, which states that the nullity of a block in a matrix equals the nullity of the complementary block in its inverse matrix. Here, the nullity is the dimension of the kernel. The theorem was proven in an abstract setting by , and for matrices by. Partition a matrix and its inverse in four submatrices: The partition on the right-hand side should be the transpose of the partition on the left-hand side, in the sense that if A is an m-by-n block then E should be an n-by-m block. The statement of the nullity theorem is now that the nullities of the blocks on the right equal the nullities of the blocks on the left: More generally, if a submatrix is formed from the rows with indices {i1, i2, …, im} and the columns with indices {j1, j2, …, jn}, then the complementary submatrix is formed from the rows with indices {1, 2, …, N} \ {j1, j2, …, jn} and the columns with indices {1, 2, …, N} \ {i1, i2, …, im}, where N is the size of the whole matrix. The nullity theorem states that the nullity of any submatrix equals the nullity of the complementary submatrix of the inverse. (Wikipedia).

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Rank Nullity Theorem

Proof of the Rank-Nullity Theorem, one of the cornerstones of linear algebra. Intuitively, it says that the rank and the nullity of a linear transformation are related: the more vectors T sends to 0, the smaller its range. The proof is especially elegant and uses important concepts in line

From playlist Linear Transformations

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Null Spaces And Ranges

Definitions of null space, injectivity, range, and surjectivity. Fundamental theorem of linear maps. Consequences for systems of linear equations.

From playlist Linear Algebra Done Right

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What is a Null Hypothesis?

Overview of null hypothesis, examples of null and alternate hypotheses, and how to write a null hypothesis statement.

From playlist Hypothesis Tests and Critical Values

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Prove a Null Space is a Subspace

This video provides a basic proof that a null space is a subspace.

From playlist Column and Null Space

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Null space of a matrix example

In today's lecture I work through an example to show you a well-known pitfall when it comes to the null space of a matrix. In the example I show you how to create the special cases and how to use them to represent the null space. There is also a quick look at the NullSpace function in Ma

From playlist Introducing linear algebra

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Null points and null lines | Universal Hyperbolic Geometry 12 | NJ Wildberger

Null points and null lines are central in universal hyperbolic geometry. By definition a null point is just a point which lies on its dual line, and dually a null line is just a line which passes through its dual point. We extend the rational parametrization of the unit circle to the proj

From playlist Universal Hyperbolic Geometry

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53 - The rank-nullity theorem revisited

Algebra 1M - international Course no. 104016 Dr. Aviv Censor Technion - International school of engineering

From playlist Algebra 1M

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Linear Algebra - Lecture 32 - Dimension, Rank, and Nullity

In this video, I define the dimension of a subspace. I also prove the fact that any two bases of a subspace must have the same number of vectors, which guarantees that dimension is well-defined. Finally, I define the rank and nullity of a matrix, and explain the Rank-Nullity Theorem.

From playlist Linear Algebra Lectures

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Linear Transformations -- Abstract Linear Algebra 13

⭐Support the channel⭐ Patreon: https://www.patreon.com/michaelpennmath Merch: https://teespring.com/stores/michael-penn-math My amazon shop: https://www.amazon.com/shop/michaelpenn ⭐my other channels⭐ Main Channel: https://www.youtube.com/michaelpennmath non-math podcast: http

From playlist Abstract Linear Algebra

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WildLinAlg17: Rank and Nullity of a Linear Transformation

We begin to discuss linear transformations involving higher dimensions (ie more than three). The kernel and the image are important spaces, or properties of vectors, associated to a linear transformation. The corresponding dimensions are the nullity and the rank, and they satisfy a simple

From playlist A first course in Linear Algebra - N J Wildberger

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52 - The rank of T

Algebra 1M - international Course no. 104016 Dr. Aviv Censor Technion - International school of engineering

From playlist Algebra 1M

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49 - Ker(T) and Im(T)

Algebra 1M - international Course no. 104016 Dr. Aviv Censor Technion - International school of engineering

From playlist Algebra 1M

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39 - The rank-nullity theorem

Algebra 1M - international Course no. 104016 Dr. Aviv Censor Technion - International school of engineering

From playlist Algebra 1M

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Invertible Matrix Theorem -- Abstract Linear Algebra 16

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From playlist Abstract Linear Algebra

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Null Space: Is a Vector in a Null Space? Find a Basis for a Null Space

This video explains how to determine if a vector is in a null space and how to find a basis for a null space.

From playlist Column and Null Space

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Null space of a matrix

In this video I start to discuss the idea of the null space of a matrix. In these situations, the right-hand side of all the equations in the linear system is equal to zero. There is the trivial solution, where all the elements of the solution is zero. We are more interested in the spec

From playlist Introducing linear algebra

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Dimension and Isomorphism

In this video, I show that two vector spaces are isomorphic if and only if they have the same dimension. This is an important fact in linear algebra. The proof is very cute and uses the linear extension theorem which I talked about in another video. Enjoy! Linear Extension Theorem https:/

From playlist Linear Transformations

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