Given,
(1+sin92π−icos92π1+sin92π+icos92π)3
Now let z=sin92π+icos92π,
So, zˉ=sin92π−icos92π=z1
So, (1+sin92π−icos92π1+sin92π+icos92π)3
=(1+zˉ1+z)3
=(1+z11+z)3
=z3(1+z1+z)3
=z3
=(sin92π+icos92π)3
=i3(cos92π−isin92π)3
=−i(cos(3×92π)−isin(3×92π))
=−i(cos32π−isin32π)
=−i(2−1−i23)
=−21(3−i)