I have the matrix H:

A11=a+bi

A12=c+di

A21=-c+di

A22=a-bi

I need to show that the equation x^2=-1 has infinitely many solutions in H.

I ignored a (because the book told me to) and so I have the matrix:

A11=bi

A12=c+di

A21=-c+di

A22=-bi

where b^2+c^2+d^2=1.

I'm just having trouble showing the "infinitely many solutions in H" part.