Question

if x-1/x = 3 then find x+1/x and x²-1/x²​

Answer 1

Answer:

x²+1/x² = 11

Explanation:

Given

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

On Squaring equation (1), we get

=> (x-1/x)² = 3²

=> x²+1/x²-2*x*(1/x) = 9

/* By algebraic identity :

(a-b)² = a²+b²-2ab */

=> x²+1/x² - 2 = 9

=> x² + 1/x² = 9 +2

=> x² + 1/x² = 11

Therefore,

x²+1/x² = 11