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{\bf Quiz 4}
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Name:
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Let $V$ and $W$ be vector spaces.
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Define what is an isomorphism between $V$ and $W$.
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Define what is means for $V$ to be isomorphic to $W$.
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Let $V$ and $W$ be vector spaces. Let $T:V\to W$ and $U:W\to V$ be
linear transformations so that $U\circ T:V\to V$ is an isomorphism.
Prove that $T$ is one-to-one.
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