Question

if x = 3+2 root 2, find the value of x2+1/x2 =18​

Answer 1

Answer:

given

x= 3+2√2

x²= (3+2√2)²

= 9+8+12√2

=. 17+12√2

1/x²= 1/(3+2√2)

= (3-2√2) rationalize

so x²+1/x²= 17+12√2+3-2√2

=. 20+10√2

x²+1/x²= 10(2+√2). ans