Question

If x=(3+√8 find value of(xsqure +1/xsquare)

Answer 1

x=3+√8..It is clearly visible that the difference between the squares of 3 and √8 is of 1.
And when this condition satisfies then,
1/x=3-√8.. Not only in this case but wherever this condition satisfies you can just change the sign....
Now you have,
x=3+√8 and 1/x=3-√8
So, x+1/x= 3+√8+3-√8= 6
And, xsq.+1/xsq.= x+1/x whole sq. -2×x×1/x
from here x and 1/x get cancelled.
So you are left with x+1/x whole sq. -2
putting the value of x+1/x=6
We will get 6sq.-2=36-2 =34..
Hence correct answer is 34...

Hope this helps!!!!!