Let
f(z) = 2z if z is not real
f(z) = z if z is real
Find f(i) + f(1) + f(-1) + f(-i).
so, 2z + z + z + 2z.
This equals 6z
-Vinculum
Use the definition directly.
f(i) + f(1) + f(-1) + f(-i)
= 2i + 1 + (-1) + (-2i)
= 0
