Understanding Injectivity and Surjectivity of Transformed Vectors

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In summary, the properties of T' being injective and surjective depend on the linear independence and spanning of the basis vectors of U and W respectively. And in order for T' to be an isomorphism, the basis of V must also be linearly independent and span the entire space of V*.
  • #1
InbredDummy
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for #2

i have the matrix:
1 1
1 0
1 0
1 0
0 0
0 0
0 0

my reasoning is that when we extended the basis of U to the basis of V, we added 3 vectors (v1,v2,v3) and in order to have T(u)=T'(u), we need to send (v1,v2,v3) to zero.

however the injective part I'm not sure about. i don't know if the null space is {0}. and the surjectivity I'm not too sure about either. and in general, I'm not sure what conditions on U,V,W,T would garner T' to be injective or surjective.

for #5:
i'm not surewhat the e* elements are exactly. so I'm really lost on this one.
 

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  • #2


Thank you for sharing your thoughts and questions about the matrix and its properties.

Firstly, I would like to clarify that the matrix you have provided is not enough information to fully understand the properties of T. We would need to know the specific definitions of U, V, W, and T in order to determine the injectivity and surjectivity of T'.

However, based on the information provided, I can offer some general insights. In order for T' to be injective, the null space of T' must be {0}. This means that the only vector that is mapped to 0 by T' is the zero vector. In order for this to happen, there must be no non-zero vectors in the domain of T' that are mapped to 0 by T. This would require the basis of U to be linearly independent, so that the vectors v1, v2, and v3 cannot be written as linear combinations of each other.

For surjectivity, T' would need to map every element in the range of T to an element in the range of T'. This would require the basis of W to span the entire range of T, so that every element in the range of T can be written as a linear combination of the basis vectors of W.

As for #5, the e* elements are the basis vectors of the dual space of V, denoted as V*. The dual space is the set of all linear functionals, or linear maps from V to the field of scalars. In order for T' to be an isomorphism, it must be an injective and surjective linear map. This means that for every non-zero element in V*, there must be a unique element in V that maps to it. This would require the basis of V to be linearly independent and span the entire space of V*. I hope this helps clarify your understanding. Thank you for your interest in this topic.
 

1. What is injectivity and surjectivity?

Injectivity and surjectivity are properties of mathematical functions that describe the relationship between the input and output values of the function. A function is injective if each input value corresponds to a unique output value, and surjective if every output value has at least one corresponding input value.

2. How do you determine if a transformed vector is injective?

To determine if a transformed vector is injective, you can use the vertical line test. This involves drawing vertical lines through the transformed vector and checking if each line intersects the vector at only one point. If this is the case, then the vector is injective.

3. Can a transformed vector be both injective and surjective?

Yes, a transformed vector can be both injective and surjective. This means that every input value has a unique output value and every output value has at least one corresponding input value.

4. How does injectivity and surjectivity relate to bijectivity?

A function that is both injective and surjective is called a bijective function. This means that the function is one-to-one and onto, and has a unique inverse function. In other words, every input value has a unique output value and vice versa.

5. Why is understanding injectivity and surjectivity important in mathematics?

Understanding injectivity and surjectivity is important in mathematics because it helps us determine the behavior and properties of mathematical functions. It also allows us to identify and solve problems involving functions, such as finding the inverse of a function or determining if a function has a unique solution.

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