Ok我無睇x domain=0,所以用domain=R解釋,但就算x domain=0:
y1=x, e^iy=e^ix, y=(ln(cos x +i sin x))/i, dydx=1/i(-sin x+i cos x)/(cos x+i sin x)
y2=-x, e^(i(-y))=e^ix, y=-(ln(cos x +i sin x))/i, dydx=-1/i(-sin x+i cos x)/(cos x+i sin x)
個x一樣係domain=0,兩個function咪一樣係orthogonal