(7+4i)/(-1+i)=(z_1)/(z_2)
rho_1=sqrt(7^2+4^2)=sqrt(49+16)=sqrt(65)
theta_1=arctan(4/7)
rho_1=sqrt(1^2+1^2)=sqrt(1+1)=sqrt(2)
theta_1=arctan((-1)/1)=arctan(-1)=((3pi)/4),
color(blue)((z_1)/(z_2)=(rho_1)/(rho_2)*e^[(theta_1-theta_2i)]
(z_1)/(z_2)=(sqrt(65))/sqrt(2)*e^(arctan(4/7i)-(3pi)/4i)
(z_1)/(z_2)=(sqrt(65/2))*e^((arctan(4/7)-(3pi)/4))i
(z_1)/(z_2)~~~5.701*e^(-1.837i)