If x2 - 8x + 1= 0  and x > 1, then the value of x3 + \(\frac{1}{x^3}\) will be:

512 488 486 686

488

If x2 - 8x + 1= 0 Divide by x on both sides, x +  \(\frac{1}{x}\) = 8 x3 + \(\frac{1}{x^3}\)  = 83 - 3 × 8 = 488   Note - if x +  \(\frac{1}{x}\) = a then x3 + \(\frac{1}{x^3}\) =  a3 - 3a