Question

Integration of csc^2(9x)dx​

Answer 1

`\displaystyle \int csc^2(9x) dx \\\\=\frac 19\displaystyle \int \csc^2 u ~du~~~~~~~;\left[\text{Let}~u= 9x \implies dx = \frac{du}9\right]\\\\=-\frac 19 \cot u + C\\\\=-\frac 19 \cot(9x)+C`