Question on lim x→2 f(4x^2 − 11) = 8?

  • Thread starter alaa amed
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In summary, the question asks whether the statement "if f is continuous at 5 and f(5) = 8 and f(4) = 3, then lim x→2 f(4x^2 − 11) = 8" is true or false. The solution involves writing the given function as the composition of two functions, determining the continuity of the inner function, and using the property that the composition of two continuous functions is also continuous. Ultimately, it is concluded that the statement is false.
  • #1
alaa amed
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Homework Statement



Determine whether the statement is true or false.
If f is continuous at 5 and f(5) = 8 and f(4) = 3, then
lim x→2 f(4x^2 − 11) = 8.

2. Homework Equations

lim x->a f(x) = f(a)

The Attempt at a Solution



I think the answer to this question is false because limit of f(4x^2 − 11) has to be approaching 8 but I am not sure if this is the right way ti think about this.[/B]
 
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  • #2
Write ##x\mapsto f(4x^2 − 11)## as the composition of two functions ##f## and ##g##, where ##g(x)=4x^2-11##.
Is ##g## continuous?
What can we say about the composition of two continuous functions?
 

FAQ: Question on lim x→2 f(4x^2 − 11) = 8?

What does the notation "lim x→2" mean?

The notation "lim x→2" means the limit as x approaches 2. In this context, it refers to the value that a function approaches as the input (x) gets closer and closer to the value 2.

What does f(4x^2 − 11) represent?

f(4x^2 − 11) represents the function f with an input of 4x^2 − 11. In other words, it is the value of the function at the point 4x^2 − 11.

What is the significance of the limit equaling 8?

The limit of a function represents the value that the function approaches as the input approaches a certain value. In this case, the limit being equal to 8 means that as x gets closer and closer to 2, the value of f(4x^2 − 11) also gets closer and closer to 8.

How can we solve this limit?

This limit can be solved using various methods, such as substitution, factoring, or algebraic manipulation. However, the specific method would depend on the given function f(4x^2 − 11).

What is the importance of understanding limits in mathematics?

Limits are important in mathematics because they allow us to understand the behavior of functions and how they change as the input changes. They also play a crucial role in calculus and are used to define derivatives and integrals, which are fundamental concepts in higher mathematics and many fields of science.

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