If $$x - \frac{1}{x} = 4$$, then the value of $$x^3 - \frac{1}{x^3}$$ is:​

Correct option is A

Given:

​$$x-\dfrac{1}{x}=4$$​​

Formula Used:
​$$a^3-b^3=(a-b)^3+3ab(a-b)$$​​

Solution:
Here a = x; b$$=\dfrac{1}{x}$$​; ab = 1.
​$$x^3-\frac{1}{x^3}=(x-\frac{1}{x})^3+3\times1\times\left(x-\frac{1}{x}\right)$$​​
=$$4^3+3\times4=64+12=76$$​​
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