Question

If (a1,a2,a3......an) are in A>P> with common difference d. then the sum of the series: sin d [cosec a1.cosec a2 + cosec a2.cosec a3 +........+ cosec a(n-1).cosec an ] is what ??

Answer 1

hey this is too complicated to understand u must post pic of this question if u r in 10 then i may try to help u