Find the value of _ r=1 ^ 5 [ ( 2 r 7 )- icos ( 2 r 7 ) ]
Mathematics · JEE Main · NTA Exams — Complex Numbers and Quadratic Equations
Find the value of \(\sum_{r=1}^{5}\left[\sin \left(\frac{2 \pi r}{7}\right)-\operatorname{icos}\left(\frac{2 \pi r}{7}\right)\right]\)
- 0
- i
- 1
- -i
Answer
(A) 0
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