11th Class
Mathematics
Sample Paper
Maths Olympiad Model Paper-7
question_answer
The value of \[\sum\limits_{k=1}^{13}{\frac{1}{\sin \,\left( \frac{\pi }{4}+\frac{(k-1)\pi }{6} \right)\,\,\sin \,\,\left( \frac{\pi }{4}+\frac{k\pi }{6} \right)}}\] is equal to