a+bia+bi in polar form is rcostheta+irsinthetarcosθ+irsinθ, where r=sqrt(a^2+b^2)r=√a2+b2 and theta=arctan(b/a)θ=arctan(ba)
8i=0+8i8i=0+8i hence r=sqrt(0^2+8^2)=8r=√02+82=8 and theta=arctan(8/0)=arctanooθ=arctan(80)=arctan∞ and one can say theta=pi/2θ=π2
8i=8(cos(pi/2)+isin(pi/2))8i=8(cos(π2)+isin(π2))