If $x^2 - 6\sqrt{3} x + 1= 0, $ then the value of $x^3 + \frac{1}{x^3}$ will be :
Answer & explanation
Correct answer: option 4
We know that,
If x + \(\frac{1}{x}\) = n
then, $x^3 +\frac{1}{x^3}$ = n3 - 3 × n
If $x^2 - 6\sqrt{3} x + 1= 0, $
then the value of $x^3 + \frac{1}{x^3}$
Divide by x on both the sides of If $x^2 - 6\sqrt{3} x + 1= 0, $ then we get,
x + \(\frac{1}{x}\) = $6\sqrt{3}$
then the value of $x^3 + \frac{1}{x^3}$ = ($6\sqrt{3}$)3 - 3 × $6\sqrt{3}$ = $648\sqrt{3}$ - $18\sqrt{3}$ = $630\sqrt{3}$