Proving f=0 on [a,b] with Analysis

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Repeating this argument, we find that fn-1(x), fn-2(x), ..., f1(x) are all identically 0 on [a, b]. Finally, since f(x) = f0(x) = 0 for all x in [a, b], we have proven that f(x) is identically 0 on [a, b].In summary, the conversation discusses proving that f is identically equal to 0 on [a, b] given that fn(x) is equal to 0 for all x in [a, b]. This is proven using the fundamental theorem and the fact that the derivative of f_n(x)= \int_a^x f_{n-1}(t
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Homework Statement


[tex]f[/tex] is continuous on [a,b]
[tex]f_{1}(x)=\int^x_a f(t)dt[/tex]
[tex]f_{2}(x)=\int^x_a f_{1}(t)dt [/tex]
...
[tex]\forall x\in[a,b],\exists n[/tex] depends on x , such that [tex]f_{n}(x)=0.[/tex]
prove that [tex]f\equiv0.[/tex]

Homework Equations


mathematical analysis

The Attempt at a Solution


copy the taylor theorem 's proof?
but I get nothing.
 
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If, for some n, fn is identically 0, then it is a constant and so its derivative is identically equal to 0. But, by the fundamental theorem, the derivative of [itex]f_n(x)= \int_a^x f_{n-1}(t)dt[/itex] is fn-1(x). Therefore, if fn(x) is identically 0 on [a, b], so is fn-1(x).
 

1. How do you prove that f=0 on [a,b] using Analysis?

To prove that f=0 on [a,b], we use the definition of a continuous function. We start by assuming that f is not equal to 0 on [a,b]. Then, using the Intermediate Value Theorem, we can find a point c in [a,b] such that f(c)=0. This contradicts our assumption and therefore, f must be equal to 0 on [a,b].

2. What is the importance of proving f=0 on [a,b] with Analysis?

Proving f=0 on [a,b] using Analysis is important because it helps us understand the behavior of the function on the interval [a,b]. It also allows us to make conclusions about the properties of the function, such as continuity and differentiability.

3. Are there any other methods to prove f=0 on [a,b] besides using Analysis?

Yes, there are other methods such as using the Fundamental Theorem of Calculus or using the definition of a Riemann integral. However, using Analysis is a more general and rigorous approach that can be applied to a wider range of functions.

4. Can you give an example of proving f=0 on [a,b] with Analysis?

Sure, let's say we have a function f(x)=sin(x) on the interval [0,π]. To prove that f=0 on [0,π], we assume that f is not equal to 0 and use the Intermediate Value Theorem to find a point c in [0,π] such that f(c)=0. But since f(x)=sin(x) can only equal 0 at x=0 and x=π, this contradicts our assumption and therefore, f must be equal to 0 on [0,π].

5. Can proving f=0 on [a,b] using Analysis be used for any type of function?

Yes, proving f=0 on [a,b] with Analysis can be used for any continuous function on the interval [a,b]. However, the specific techniques and methods used may vary depending on the properties of the function.

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