यदि `x-1/x=2` तो निम्नलिखित का मान क्या होगा-`x^(3)-1/(x^(3))=?`

Options

A. 2
B. 11
C. 15
D. 14

Answer

D

Explanation

`x-1/x=2` to find `x^(3)-1/(x^(3))=?`
`implies x-1/x=2implies(x-1/x)^(3)`
`=2^(3)` cubing both side
`implies x^(3)-1/(x^(3))-3xx x xx 1/x(x-1/x)=8`
`implies x^(3)-1/(x^(3))-3xx 1xx(2)=8`
`implies x^(3)-1/(x^(3))=14`