1.

If x+1/x=4 then find the value of x^3+1/x^3

Answer»
x +  \frac{1}{x}  = 4


CUBE on both SIDES,



= >  {x}^{3}  +  \frac{1}{ {x}^{3} }  + 3(x \times  \frac{1}{x} )( x +  \frac{1}{x} ) = 64 \\  \\  = >  {x}^{3}   +  \frac{1}{ {x}^{3} }  + 3(1)(4) = 64 \\  \\  = >  {x}^{3}   +  \frac{1}{ {x}^{3} }   = 6 4 - 12 \\  \\  {x}^{3}  +  \frac{1}{{x}^{3} }  = 52


Discussion

No Comment Found

Related InterviewSolutions