Grouping the positive and negative terms separately:
sin1∘α=(∑k=3059cot(2k∘))−(∑k=3059cot((2k+1)∘))
By symmetric cancellation using cot(180∘−θ)=−cotθ, all pairs in the second sum cancel to zero, and in the first sum all terms cancel except for cot60∘:
sin1∘α=cot60∘=31
Rearranging gives:
αcsc1∘=3
Squaring both sides yields:
(αcsc1∘)2=3
Evaluate Trigonometric Series Sum and Cosecant Ratio Squared | Mathematics PYQ Solution - JEE Challenger