Finding the limits of this expression

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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:
v6nqcy.png


Attempt no. 2:
357keme.png
 
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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
 
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!
 
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