Сложение векторов

z_1=x_1+iy_1=r_1 left ( cos%phi_1 + i sin%phi_1 right ) newline
z_2=x_2+iy_2=r_2 left ( cos%phi_2 + i sin%phi_2 right ) newline
z_3=z_1+z_2= left ( x_1+x_2 right)+ i left ( y_1+y_2 right)=left ( r_1  cos%phi_1+r_2  cos%phi_2 right)+ i left (r_1 sin%phi_1+r_2 sin%phi_1 right)=r_3 left ( cos%phi_3+i sin%phi_3 right ) newline
left lbrace  alignl {stack
{r_3 cos%phi_3=r_1  cos%phi_1+r_2  cos%phi_2 #
r_3 sin%phi_3=r_1 sin%phi_1+r_2 sin%phi_1}} right none newline
left lbrace alignl { stack{
r_3=sqrt {left ( r_1  cos%phi_1+r_2  cos%phi_2 right)^2+left ( r_1 sin%phi_1+r_2 sin%phi_1 right )^2} #
nitalic tg%phi_3={ r_1 sin%phi_1+r_2 sin%phi_1 } over {r_1  cos%phi_1+r_2  cos%phi_2}
}} right none