(1+x)^5=(1-z)^5=ρ^5*e^(5iθ)
1+x=ρ*e^[i(2kπ+5θ)/5]
1+x
=ρ*e^[i(2kπ+5θ)/5]
=ρ(e^iθ)*e^(i2kpi/5)
=(1-z)e^(i2kpi/5)