Question

if x=2+root3 under cube root then x cube+1by x cube=?

Answer 1

x³=(2+√3)³=26+15√3

and 1/x³=1/(26+15√3)=26-15√3 (by rationalising)

So, x³+1/x³=26+15√3+26-15√3=52

Answer 2

given,x=2+root3 under cube root
x^3=2+root3
1/x^3=2-root3
x^3+1/x^3=2+root3 + 2-root3=2