Question

If x = (3+v8), find the value of (x2 +1/x2)​

Answer 1

It is given that x=(3+√8)

Then 1/x=1/(3+√8)=(3-√8)/(3²-8)=(3-√8)

therefore,

(x+1/x)²=x² + 1/x² +2

or, x² + 1/x² =( 3+√8)² - (3-√8)²

=9+8+6√8 -9-8+6√8

=12√8

24√2