Question

X^2+1/x^2=38, then the value of x+1/x is

Answer 1

Hello!

let x + 1/x = z

Squaring on both sides we have

( x + 1/x )² = z²

x² + 1/x² + 2x ( 1/x ) = z²

Becoz ( a + b )² = a² + b² + 2ab

x² + 1/x² + 2 = z²

z² = 38 + 2

z² = 40

z = ±√(40)

z = ±2√(10)

x + 1/x = ±2√(10)

HOPE IT HELPS.