Assuming that
( i ) = (1/2)
+ i (1/2)
we can square both sides to get
i = [ (1/2) + i (1/2)
]2
i = [ (1/2) + 2(1/2) i + (1/2) i2 ]
i = [ (1/2) + i + (1/2) (-1) ]
i = i (which is a true statement)
This is not a proof, but simply evidence that the formula is correct.