Question

if x2+1/x2=38 so find the value of x3-1/x3

Answer 1

(x+1/x)^2
=(x^2+1/x^2)+2
=38+2
=40
x+1/x=√40

x^3+1/x^3=(x+1/x)[(x^2+1/x^2 +2)-3]
=(√40)(38+2-3)
=(√40)(37)
=37√40
=37*2√10
=74√10

Answer 2

Hi brother!

Here is your answer
==============================
(x - 1/x)² =x² + 1/x² -2

= 38 -2

= 36

(x - 1/x)² = 36

(x - 1/x) = 6

x³ - 1 /x³ = ( x - 1/x ) (x² + x × 1/x + 1/x²)

Then cancelled x ×1/x
Now,

=> 6 × ( x² + 1/x² +1)
=>6× (38+1)

=> 6×39

=> 234 Ans

Hope it's helpful!