Find 20000ϕ(20000) using the formula for the Euler ϕ-function. (b) Find ∣z₂₀₀₀₀∣and∣u₂₀₀₀₀∣.
a)ϕ(20000)=8000, ∣z₂₀₀₀₀∣=20000, ∣u₂₀₀₀₀∣=19999
b)ϕ(20000)=12000, ∣z₂₀₀₀₀∣=19999, ∣u₂₀₀₀₀∣=20000
c)ϕ(20000)=16000, ∣z₂₀₀₀₀∣=19999,∣u₂₀₀₀₀∣=19998
d)ϕ(20000)=20000,∣z₂₀₀₀₀∣=19998, ∣u₂₀₀₀₀∣=19999