CUET Preparation Today
If a + \(\frac{1}{a + 4}\) = 5 Then find , (a + 4)3 + \(\frac{1}{(a + 4)^3}\) |
729 730 702 700 |
702 |
Given = a + \(\frac{1}{a + 4}\) = 5 By adding 4 on both sides we get, (a + 4) + \(\frac{1}{a + 4}\) = 5 + 4 = 9 (a + 4)3 + \(\frac{1}{(a + 4)^3}\) = 93 - 3 × 9 = 702
Note - if x + \(\frac{1}{x}\) = a then x3 + \(\frac{1}{x^3}\) = a3 - 3a |
