A simple exponential simplification

[fredrik-johansson]

>>> exp((log(2*i) - pi*i/2)/2)
1.41421 + 0e-34*I {-a*b+a where a = 0.707107 + 0.707107*I [a^4+1=0], b = I [b^2+1=0]}

It would look better if this just output sqrt(2).