Question

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

Answer 1

$x + \frac{1}{x} = 4$


Cube on both sides,



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

Answer 2

Heya !!



X + 1/X = 4







Cubing both sides ,



( X + 1/X )³ = (4)³





X³ + 1/X³ + 3 × X × 1/X × ( X + 1/X ) = 64





X³ + 1/X³ + 3 × 4 = 64




X³ + 1/X³ = 52