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Mathematics
Mathematics
Problem
The value of
∑
k
=
1
10
(
sin
2
k
π
11
+
i
cos
2
k
π
11
)
\sum_{k=1}^{10} \left( \sin \frac{2k\pi}{11} + i \cos \frac{2k\pi}{11} \right)
∑
k
=
1
10
(
sin
11
2
k
π
+
i
cos
11
2
k
π
)
(where
i
=
−
1
i = \sqrt{-1}
i
=
−
1
) is a.
i
i
i
b. 1 c.
−
1
-1
−
1
d.
−
i
-i
−
i
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