Finding a limit when assigned restrictions to f(x)

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In summary, the problem asks to find the limit of x^4f(x) as x approaches 0, given that 0 ≤ f(x) ≥ 1 for all x. The solution involves using the squeeze theorem, as the limit can be shown to be both 0 and 1, and therefore it must exist and be equal to both values. This proves that the limit is equal to 0.
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thatguythere
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Homework Statement


Suppose 0 ≤ f(x) ≥ 1 for all x, find lim x→0 x^4f(x)


Homework Equations





The Attempt at a Solution


I'm very uncertain about how to go about doing this.
lim x→0 x^4 f(x) = 0^4 (0)
= 0
lim x→0 x^4 f(x) = 1^4 (1)
=1
How does that prove anything?
 
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  • #2
thatguythere said:

Homework Statement


Suppose 0 ≤ f(x) ≥ 1 for all x, find lim x→0 x^4f(x)
Don't you mean 0 ≤ f(x) ≤ 1?

Have you learned the "squeeze" theorem?
thatguythere said:

Homework Equations





The Attempt at a Solution


I'm very uncertain about how to go about doing this.
lim x→0 x^4 f(x) = 0^4 (0)
= 0
lim x→0 x^4 f(x) = 1^4 (1)
=1
How does that prove anything?
 

1. What does it mean to find a limit when assigned restrictions to f(x)?

Finding a limit when assigned restrictions to f(x) means determining the value that a function approaches as the input (x) gets closer and closer to a specific point, or when certain conditions or limitations are placed on the function.

2. How do I know if a limit exists when there are restrictions on the function?

A limit exists when the function approaches the same value from both sides of the restricted point. This means that the function must approach the same value from the left and right side of the restricted point, regardless of any limitations or restrictions on the function.

3. Can a limit exist at a restricted point?

Yes, a limit can exist at a restricted point as long as the function approaches the same value from both sides of the restricted point.

4. How do I find the limit of a function with multiple restrictions?

To find the limit of a function with multiple restrictions, you must first determine if the function approaches the same value from both sides of each restricted point. If it does, then the limit at that point is the same value. If not, the limit does not exist at that point.

5. Are there any special rules or techniques for finding limits with restrictions?

Yes, there are some special rules and techniques for finding limits with restrictions. These include using the squeeze theorem, L'Hopital's rule, and algebraic manipulation to simplify the function before taking the limit. It is also important to pay attention to any removable discontinuities or holes in the graph of the function.

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