Find the middle term in the expansion of the `(a/b+b/a)^6`.

Explanation

`(a/b+b/a)^6`Here there is only one middle term i.e. the 4th term.
` therefore` 4th term i.e. (3+1)th term in the expansion of `(a/b+b/a)^6` is `"^6C_3 (a/b)^6-3(b/a)^3`
`6!/3!3!(a/b)^3(b/a)^3` = 6.5.4/6 = 20