A) 1
B) 0
C) -1
D) None of these
Correct Answer: B
Solution :
\[\because \]\[\alpha \] and \[\beta \] are cube roots of unity \[\therefore \] \[\alpha =\omega ,\beta ={{\omega }^{2}}\] \[{{\alpha }^{4}}+{{\beta }^{4}}+{{\alpha }^{-1}}{{\beta }^{-1}}={{\omega }^{4}}+{{\omega }^{8}}+\frac{1}{\omega }.\frac{1}{{{\omega }^{2}}}\] \[={{\omega }^{3+1}}+{{\omega }^{6+2}}+1=1+\omega +{{\omega }^{2}}=0\]You need to login to perform this action.
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