i^2=1??? How can this be? First all I must tell you people that I have no doubt that i^2=-1 but what am I doing wrong in the following steps? i^2 =i * i =sqrt(-1) * sqrt(-1) =sqrt(-1*-1) =sqrt(1)=1? I asked my mathematics teacher but he was unable to find any error in it. Thanks in advance for any help that you can offer.