Question

if x=3+2√2 find the value of x square + 1/x square

Answer 1

Given x = 3 + 2√2
⇒ x2 = 17 + 12√2
⇒ 1/x2 = 1/(17 + 12√2)
On rationalizing the denominator we get 
1/x2 = (17 – 12√2)
∴ (x2 +1/x2) =(17 + 12√2) + (17 – 12√2)
                    = 34