Question

if x+1/x=k
, prove that x3+1/x3 = K(k2-3)​

Answer 1

Heyyo refer to the attachment

Answer 2

Answer:

Given-x+1/x=k

To prove - x^3+1/x^3=k(k^2-3)

Proof- x+1/x=k

Cubing both sides,

(x^3+1/x^3)^3=k^3

x^3+1/x^3+3*x*1/x(x+1/x)=k^3

x^3+1/x^3+3*k=k^3

x^3+1/x^3+3k=k^3

x^3+1/x^3=k^3-3k

x^3+1/x^3=k(k^2-3)