$4-$ Two source are located at $(x,y)=(-1,0)$ and $(1,0)$ and a sink are located at

$(x,y)=(0,0)$ and $(2,0),$ with intensity $=U_{},$ in the presence of a uniform flow of

speed $U_{}.$ Calculate:

a$)$ The stream function and velocity potential.

b$)$ The velocity field and stagnation points.

c$)$ The stagnation streamlines.

d$)$ If you do this question as a take$-$home, plot the streamlines with MATLAB;

otherwise, skip part $($d$).$