1:-I=∫1/(sin³x) dx from 0 to ∏

Dear Mithresh

I=_o∫^π 1/(sin³x) dx 

  =_o∫^π sinx/(sin⁴x) dx

  =_o∫^π sinx/(1-cos²x)² dx

 cosx =t

-sinxdx =dt

I=₁∫^-1 -dt/(1-t²)²

 =_-1∫¹ dt/(1-t²)²

 =2 ₀∫¹ dt/(t-1)²(t+1)²

 use partial fraction and intigrate

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