Limits with cubic root without L’Hopital’s Rule: $\lim_{x\to 1}\frac{\sqrt[3]{x}-1}{x-1} $

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I need to solve

$$\lim_{x\to 1}\frac{\sqrt[3]{x}-1}{x-1} $$

But without using L’Hopital’s Rule, could someone help me?

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There are 2 best solutions below

3
On

Factorize $x-1$ as $$\left(\sqrt[3]{x}-1\right)\left(x^{2/3}+x^{1/3}+1\right)$$

6
On

Taking $f(x) = \sqrt[3]{x}$ your expression becomes $$ \lim\limits_{x \rightarrow 1} \frac{f(x) - f(1)}{x - 1} = f'(1).$$