`int 1/(sinx+sin2x)dx`.

Explanation

`I = int 1/(sinx+sin2x)dx`

`= int 1/(sinx+2sinxcosx)dx`

`= int 1/(sinx(1+2cosx)dx`

`= int sinx/(sin^2x(1+2cosx)dx`

`= int sinx/((1-cos^2x)(1+2cosx)dx`

Let `cosx = t , then -sinxdx= dt`

`:. I = int -dt/((1-t^2)(1+2t) )`

`= int -dt/((1-t)(1+t)(1+2t) )`

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