Proving (1+x)^n approaches 1 + nx when x goes to zero

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Homework Statement


I've heard this affirmation in an gravitation lecture. I thought it was interesting and decided to check it out. It turns out to be true so I decided to prove it.

I'm not a mathematician so proving stuff is not my department. Still I try to do some proofs just for fun. I hope I don't make your eyes bleed or something.


Homework Equations


\lim_{x \rightarrow 0} (1 + x)^n


The Attempt at a Solution


I'm not sure if I should try prooving by epsilon-delta or by mathematical induction (if that is even possible)
I did try by mathematical induction but it didnt look convincing

How would you do it?
 
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\lim_{x \to 0} (1 + x)^n

Apply binomial expansion to this equation and then the concept of limits.
 
Try Binomial Theorem.

While it is correct to say {(1+x)}^n \approx 1+nx for sufficiently small x, the actual limit of the expression as x tends to zero is simply 1.
 
It's impossible to prove this until you rigorized what the statement means.

I think the best rigorous version of this statement is that y=1+nx is the tangent line of y=(1+x)n at the point x=0.

Or, it could mean

\lim_{x\rightarrow 0} \frac{(1+x)^n-(1+nx)}{x}=0

which means that the functions are equal up to first order.

Try to prove these two statements.
 
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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