Practicing Success
If x2 - 10x - 1= 0 and x > 1, then the value of x3 - \(\frac{1}{x^3}\) will be: |
1030 1234 1095 970 |
1030 |
If x2 - 10x - 1= 0 Divide by x on both sides, x - \(\frac{1}{x}\) = 10 x3 - \(\frac{1}{x^3}\) = 103 + 3 × 10 = 1030
Note - if x - \(\frac{1}{x}\) = a then x3 - \(\frac{1}{x^3}\) = a3 + 3a |