Extend the functional by continuity (Functional analysis)

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The discussion focuses on extending a bounded linear operator T0 from a dense linear subspace E of a normed vector space X to a Banach space Y while maintaining its norm. The approach involves demonstrating that if a sequence (xn) converges to x, then T0(xn) forms a Cauchy sequence. The limit of this sequence is then used to define a new function f(x). Additionally, it is emphasized that T0 is uniformly continuous, which aids in proving that the extension is a well-defined bounded linear function. The deadline for the homework is approaching, prompting participants to seek clarification and assistance.
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Homework Statement



Let E be a dense linear subspace of a normed vector space X, and let Y be a
Banach space. Suppose T0 \in £(E, Y) is a bounded linear operator from E to Y.
Show that T0 can be extended to T\in £(E, Y) (by continuity) without increasing its norm.

The Attempt at a Solution


Someone kindly gave me a hint. I am trying to work out the details. The deadline is approaching. So I put the question here just in case. Thanks.
For this particular problem you want to show that if (xn) converges to x then T0(xn) is a Cauchy sequence and then define f(x) as the limit of the sequence. Finally you need to show that the map is a well-defined bounded linear function.
 
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Use that T0 is uniform continuous.
 
Thank you!
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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