Question

If `x + 1/x = 4, "then"  x^3 + 1/x^3 =` ______.

विकल्प

• 52

• 76

• 64

• 62

Answer 1

If `x + 1/x = 4, "then"  x^3 + 1/x^3 =` 52.

Explanation:

`x^3 + 1/x^3 = (x + 1/x)^3 - 3(x + 1/x)`

`x^3 + 1/x^3 = (4)^3 - 3(4)`

`x^3 + 1/x^3 = 64 - 12`

`x^3 + 1/x^3 = 52`