Question

If x^2+1/x^2=7 then x^3+1/x^3=?

Answer 1

Hey!!!....Here is ur answer

x^2+1/x^2=7

x^2+1/x^2+2=9

x+1/x=3

x^3+1/x^3+3×3=27

x^3+1/x^3=18

Hope it will help you

Answer 2

Heya ✋

Let see your answer !!!!

Given that

x^2 + 1/x^2 = 7

x^3 + 1/x^3 = ?

Solution

x^2 + 1/x^2 = 7

=> x^2 + 1/x^2 + 2 = 9

=> (x + 1/x)^2 = 9

=> x + 1/x = √9

=> x + 1/x = 3

Hence ,

x^3 + 1/x^3

= (x + 1/x) (x^2 - x × 1/x + 1/x^2)

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

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

= 3 (7 - 1)

= 3 × 6

= 18

Thanks :)))))