F(x)=\operatorname{cosec} x হলে - \begin{array}{l}\text{i. } \int F(x) d x=\ln |\operatorname{cosec} x+\cot x|+c\\\text{ii. } \int F(x) d x=\ln \left|\tan \frac{x}{2}\right|+c\\\text{iii. } \int F(x) d x=-\ln |\operatorname{cosec} x+\cot x|+c\end{array} নিচের কোনটি সঠিক?
