Question

if x+1/x=root3,evaluate x^3+1/x^3

Answer 1

Answer:

18

Step-by-step explanation:

Given: x+1/x = 3

Cubing both sides

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

Now, using the formula ( a+b)^3

x^3 + 1/x^3 + 3× x × 1/x ( x+ 1/x) = 27

x^3 + 1/x^3 + 3 (x+1/x) = 27

x^3 + 1/x^3 + 3 (3) = 27

x^3 + 1/x^3 = 27-9

x^3 + 1/x^3 = 18