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Mathematics
Mathematics
Problem
Find the value of
∑
r
=
1
4
n
+
7
i
r
\sum_{r=1}^{4n+7} i^r
∑
r
=
1
4
n
+
7
i
r
(where,
i
=
−
1
i = \sqrt{-1}
i
=
−
1
).
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