Substituting z = i you get

]]>(1+i)!

i !]]>

Those are all difficult but here goes nothing!

Let's try (.1)! first. For that we use a series and a trick.

It is in nested or Horner form for fast computation. The series is best for values >=5 so we put in z = 5.1

We take the exponential of both sides and get.

Now to get .1! we use a simple relation:

So

]]>(-1) ! does not exist. All the negative integers of the factorial function are equal to infinity.

I would use a Taylor series for some of them. How much accuracy do you need.

Basically though you would use a computer or Wolfram Alpha to look those up. If your teacher wants to see some method then how is it you do not know that method? If I use series expansion he/she may not want that method used. So provide me with what method is to be used.

]]>i !

(-1) !

(1+i) !

(.1) !]]>