Practicing Success
If x2 - 11x + 1= 0 and x > 1, then the value of x3 + \(\frac{1}{x^3}\) will be: |
1331 1298 1245 0 |
1298 |
If x2 - 11x + 1= 0 Divide by x on both sides, x + \(\frac{1}{x}\) = 11 x3 + \(\frac{1}{x^3}\) = 113 - 3 × 11 = 1298
Note - if x + \(\frac{1}{x}\) = a then x3 + \(\frac{1}{x^3}\) = a3 - 3a |