How bad is this statement regarding the Fundamental Theorem for Line Integrals?

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SUMMARY

The Fundamental Theorem for Line Integrals states that for a vector field F, if there exists a function f such that F = grad f, then the integral of F along a continuous, oriented curve C from point P to point Q is given by the equation ∫C F · dr = f(Q) - f(P). The discussion highlights the importance of accurately stating the theorem, including all necessary conditions, as omitting details such as the continuity of the curve can lead to incorrect conclusions. A specific counterexample is provided, demonstrating that the theorem's application requires careful consideration of the vector field's properties.

PREREQUISITES
  • Understanding of vector fields and gradients
  • Familiarity with line integrals and their properties
  • Knowledge of continuity and orientation in calculus
  • Ability to analyze mathematical statements and their conditions
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  • Review the Fundamental Theorem for Line Integrals in multiple calculus textbooks
  • Study the properties of continuous and differentiable functions in vector calculus
  • Learn about counterexamples in mathematical theorems to understand limitations
  • Explore the concept of integrability in vector fields and its implications
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Students of calculus, mathematics educators, and anyone seeking to deepen their understanding of vector calculus and the application of the Fundamental Theorem for Line Integrals.

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State the Fundamental Theorem:

Let F be a vector field.

If there exists a function f such that F = grad f, then

[itex]\int_{C} F \cdot dr = f(Q) - f(P)[/itex]

where P and Q are endpoints of curve C.

_________________________________

I didn't receive any credit for this answer. Admittedly, it's not very good. I failed to mention that C is a continuous, oriented curve among other things.

But when I asked my professor about why I received no credit, she opened the textbook and said "THAT is the theorem." She wanted it word for word, claiming that was the difference between asking for the Theorem and definition.

So, my question is, what is the actual guideline for writing a theorem? Obviously, she wanted it word for word, but as far as I know my textbook doesn't give it work for word what some other textbook would.
 
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Missing any requirement of the theorem's precept may make the resulting equation invalid. For example, as your statement stands, it is false. Consider F(x) = {(2x)sin(1/x^2) - (2/x)cos(1/x^2), when x is non-zero and 0 when x = 0} and the curve C parametrized by r(t) = x(t) = t, -1 <= t <= 1. F is the gradient of a function, so it fits your theorem, but the equation does not hold, as F is not even integrable on C. Someone who applied your theorem to this case without checking the continuity of F over C would end up with a number that does not mean anything.
I doubt your teacher expects you to regurgitate the exact words used by a particular author to state a theorem; she probably just wanted you to look at the theorem again and see the concepts that are missing from your statement.
 
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