Find the two middle terms in the expansion of : (i) `(x^(2)+a^(2))^(5)` (ii) `(x^(4)-1/x^(3))^(11)`

Find the two middle terms in the expansion of : (i) `(x^(2)+a^(2))^(5)` (ii) `(x^(4)-1/x^(3))^(11)` `(p/x +x/p)^(9)` (iv) `(3x-x^(3)/6)^(9)`