If x2 - 11x - 1= 0 and x > 1, then the value of x3 - \(\frac{1}{x^3}\) will be: |
1356 1364 1360 1370 |
1364 |
If x2 - 11x - 1= 0 Divide by x on both sides, x - \(\frac{1}{x}\) = 11 x3 - \(\frac{1}{x^3}\) = 113 + 3 × 11 = 1364
Note - if x - \(\frac{1}{x}\) = a then x3 - \(\frac{1}{x^3}\) = a3 + 3a |