Finding the limits of this expression

In summary, the conversation discusses two attempts at solving a problem, with attempt no. 1 being questioned by the speaker. Attempt no. 2 is deemed more rigorous and the conversation goes on to explain the difference between F'(2) and F(2)', using the example of Taylor's expansion. The issue with attempt no. 1 is resolved and the conversation ends with a thank you.
  • #1
unscientific
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Homework Statement



I did two attempts. I find attempt no. 1 slightly fishy and attempt 2 more rigorous. Can anyone tell me what's wrong with attempt no. 1?



The Attempt at a Solution



Attempt no. 1:
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Attempt no. 2:
357keme.png
 
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  • #2
They are both basically right. In one though
(F(x)-F(2))'=F'(x)-0=f(x)
F(2)' is not equal to F'(2)

This can be seen as the derivative of the anti-derivative of sin(x)/x

or the average of sin(x)/x over x near 2

in either case we get

sin(2)/2
 
  • #3
lurflurf said:
They are both basically right. In one though
(F(x)-F(2))'=F'(x)-0=f(x)
F(2)' is not equal to F'(2)

This can be seen as the derivative of the anti-derivative of sin(x)/x

or the average of sin(x)/x over x near 2

in either case we get

sin(2)/2

An example of F'(2) would be say...the first f' term in the taylor's expansion. F(2)' would be say, differentiating the constant term in taylor's expansion.

I see what you mean..thanks!
 

FAQ: Finding the limits of this expression

What is the importance of finding the limits of an expression?

Finding the limits of an expression is important because it allows us to determine the behavior of a function at specific points or as it approaches certain values. This information is crucial in understanding the properties and characteristics of a function.

How do you find the limit of an expression?

To find the limit of an expression, we can use various methods such as substitution, factoring, rationalization, and L'Hopital's rule. These methods involve manipulating the expression algebraically or using calculus techniques to evaluate the limit.

What does the limit of an expression represent?

The limit of an expression represents the value that a function approaches as the input approaches a certain value. It can also represent the behavior of a function at a specific point or as it tends towards infinity or negative infinity.

Can a function have a limit at a point where it is not defined?

Yes, a function can have a limit at a point where it is not defined. This is known as a removable discontinuity, and it occurs when the function has a hole or gap at that point. The limit still exists and can be evaluated by using algebraic or graphical methods.

How can finding the limits of an expression be useful in real-life applications?

Finding the limits of an expression is useful in real-life applications, such as in physics, engineering, and economics. It allows us to model and predict the behavior of systems and functions, which is crucial in making informed decisions and solving real-world problems.

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