<prompt> Kokotafrac121990 sum_n 0995 -3n binom19902n.  <response>: Kwa nadharia ya Binomial,anzaalign1 i sqrt31990 binom19900 binom19901 i sqrt3 binom19902 i sqrt32 binom19903 i sqrt33 binom19904 i sqrt34 nukta binom19901990 i sqrt31990 binom19900 i binom19901 sqrt3 - 3 binom19902 3i sqrt3 binom19903 32 binom19904 dots - 3995 binom19901990.endalignKwa hivyo, sum_n 01995 -3n binom19902n ndio sehemu halisi ya 1 i sqrt3 1990.Na nadharia ya DeMoivre,anzaalign1 i sqrt31990 2 jina la mwendeshajicis 60circ1990 21990 jina la operetacis 119400circ 21990 jina la operetacis 240circ 21990 kushoto -frac12 - i fracsqrt32 kulia.mwishoalignKwa hiyo,frac121990 sum_n 0995 -3n binom19902n -frac12. 