What Constitutes a Vector Space in Function Sets?

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The discussion clarifies the concept of function sets in linear algebra, specifically the notation F(S, F), which represents all functions mapping from a nonempty set S to a field F. It confirms that a function in F(S, F) can take any value from S and produce a corresponding value in F. The operations of addition and scalar multiplication for these functions are defined in a familiar manner, aligning with standard algebraic practices. Additionally, it addresses the notation RX, indicating that it is equivalent to F(X, R) when R represents the real numbers. Understanding these concepts is crucial for grasping vector spaces in the context of function sets.
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Homework Statement



Hello, this is not a problem but I want some clarification with the following paragraph (starting my linear algebra course!):

Let S be any nonempty set and F be any field*, and let F(S,F) denote the
set of all functions from S to F. Two functions f and g in F(S, F) are called
equal if f(s) = g(s) for each s in S. The set F(S,F) is a vector space with
the operations of addition and scalar multiplication defined for f, g in F(S, F)
and c in F by
(f + g)(s)=f(s)+g(s) and (cf)(s)=c[f(s)]
for each s in S. Note that these are the familiar operations of addition and
scalar multiplication for functions used in algebra and calculus.

*my prof said we can assume the field is R, all real numbers

Homework Equations


The Attempt at a Solution



What does it mean "from S to F"?
Does it mean that any function in F(S,F) can take in any values of S and produce a value in F?

I'm also confused about notation that my professor uses.
RX to denote the set {f, X->R} where R is all reals and X is some non-empty set of numbers. Does this also mean the same thing as F(X,R)?
 
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stupidmonkey said:

Homework Statement



Hello, this is not a problem but I want some clarification with the following paragraph (starting my linear algebra course!):

Let S be any nonempty set and F be any field*, and let F(S,F) denote the
set of all functions from S to F. Two functions f and g in F(S, F) are called
equal if f(s) = g(s) for each s in S. The set F(S,F) is a vector space with
the operations of addition and scalar multiplication defined for f, g in F(S, F)
and c in F by
(f + g)(s)=f(s)+g(s) and (cf)(s)=c[f(s)]
for each s in S. Note that these are the familiar operations of addition and
scalar multiplication for functions used in algebra and calculus.

*my prof said we can assume the field is R, all real numbers

Homework Equations





The Attempt at a Solution



What does it mean "from S to F"?
Does it mean that any function in F(S,F) can take in any values of S and produce a value in F?
Yes.
stupidmonkey said:
I'm also confused about notation that my professor uses.
RX to denote the set {f, X->R} where R is all reals and X is some non-empty set of numbers. Does this also mean the same thing as F(X,R)?

Yes.
 
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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