Application of complex cube root of unity

Complex cube root of unity

\[x^3-1=0\]

Step1. Using hit and trial method x=1 is one of the roots of the equation.

\[x^3-1=(x-1)(x^2+x+1)\]

\[(x-1)(x^2+x+1)=0\]

\[(x^2+x+1)=0\]

let \[ \alpha \] and \[ \beta \] are the roots of the equation \[ x^2+x+1\]=0

where \[ \alpha \] and \[ \beta \] can be found using Sridhar Acharya formula

\[\alpha =\frac{-1+\sqrt{3}i}{2}\] 

\[\beta =\frac{-1-\sqrt{3}i}{2}\]

Properties of complex numbers

let \[\omega\]=\frac{-1+\sqrt{3}i}{2}\] 

and \[\omega ^2=\frac{-1-\sqrt{3}i}{2}\]

\[\omega^3=1\]

\[ 1+\omega +\omega ^2=0\]

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