w = (α + β + 4*i) /2

=

[4*(cos(s) + i*sin(s)) + 2*(cos(t) + i*sin(t)) + 4*i] / 2

=

2*(cos(s) + i*sin(s)) + (cos(t) + i*sin(t)) + 2*i

=

[2*cos(s) + cos(t)] + i*[2*sin(s) + sin(t) + 2]


(2*cos(s), 2*sin(s)) + (cos(t), sin(t)) + (0, 2)
0 ≦ s ≦ 2*π
0 ≦ t ≦ 2*π

を図示すればよい。