The square root of a -36 simplifies to "6i". So you have 3+/- [6i/6]. The 6's cancel each other out leaving 3+/-i. So the "a" is 3 and the "b" is 1
The fourth one since it will pass the vertical test.
The second term of the expansion is
.
Solution:
Given expression:

To find the second term of the expansion.

Using Binomial theorem,

Here, a = a and b = –b

Substitute i = 0, we get

Substitute i = 1, we get

Substitute i = 2, we get

Substitute i = 3, we get

Substitute i = 4, we get

Therefore,



Hence the second term of the expansion is
.