1.
lim⁡t→0(1sin⁡2t+2sin⁡2t+⋯+nsin⁡2t)sin⁡2t\displaystyle \lim_{t\to 0} \left( \frac{1}{\sin^2 t} + \frac{2}{\sin^2 t} + \dots + \frac{n}{\sin^2 t} \right) \sin^2 t is equal to
Limit, Continuity and Differentiability - Medium - Question