Question on lim x→2 f(4x^2 − 11) = 8?

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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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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?
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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