cube root 64(cos330+isin330)

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Hello: 
cube root 64(cos330+isin330) iz the complex number with : 
z^3 = 64(cos330+isin330)   ...(1)
let:    z = r(cos(θ) +isin(θ))
so : z^3 = r^3 (cos(3θ) +isin(3θ))...(2)    ( by moivre)
by(1) and (2) :
 r^3 =64 = 4^3    and    3θ =11π/6 +2kπ k=0 , 1 , 2
r =4  and   θ  = 11π/18 +2kπ/3 k=0 , 1 , 2
coclusion : 3 cube root calculate if k = 0 , 1 ,  2

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