`1 + i^(2) + i^(4) + i^(6) = 0`.

1 + i^(2n) + i^(4n) + i^(6n)

If (i)^(2) = -1, (i)^(2) + (i)^(4) + (i)^(6) + ...... to (2n + 1) terms =

For an positive integer n, prove that : i^(n) + i^(n+1) + i^(n+2) + i^(n+3) + i^(n+4) + i^(n + 5) + i^(n+6) + i^(n+7) = 0 .

2i^4 - i^6 = ?

1+i^(2)+i^(4)+i^(6)+... .+i^(2 n)=