Question

if x = 3+√8 find the value of X+1/X

Answer 1

Step-by-step explanation:

First factorise 1/x => (1/3+ root 8)× (3-root 8 /3-root 8)

=3-root 8 /3 square - root 8 square

=3- root 8 /9-8

=3-root 8 = 1/x

Now x+1/x => 3+root 8 + 3-root 8

=+root 8 and -root 8 cancel

=3+3 =6

Answer 2

Answer:

       = 6

Step-by-step explanation:

x = 3+ √8

1 / x = 1 / (3+√8)

rationalizing

1 / x = 1 × (3-√8) / (3+√8) × (3-√8)

1 / x = (3-√8) / (3²-√8²)

1 / x = (3-√8) / 9 - 8

1 / x = (3-√8) / 1

1 / x = (3-√8)  

Put the value and find out

x + (1 / x)

= 3+ √8 + 3-√8

= 3+ 3

= 6