Question

if x^2+1/x^2=7 find x^3+1/x^3

Answer 1

HOPE IT HELPS YOU...

Answer 2

Hi ,

x² + 1/x² = 7 ----( 1 )

Add 2 both sides of the equation

x² + 1/x² + 2 = 7 + 2

( x + 1/x )² = 9

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

Now ,

x³ + 1/ x³ = ( x + 1/x ) ³ - 3(x + 1/x )

= 3³ - 3 × 3

= 27 - 9

= 18

I hope this helps you.

:)