If A = {xC : x2 = 1} and B = {xC : x4 = 1}, then write A − B and B − A.
Here,={XϵC:X2=1}
={1 ,-1}
B={xϵC:X4=1}
={1,-1,i,-i}
Now, A∖B=A∖(A⋂B)
={1,-1}∖{1,-1}
=ϕ
And B∖A=B∖(A⋂B)
={1,-1,i,-i}∖{1,-1}
={i,-i}