- #1

- 199

- 21

- Homework Statement
- $$\int \frac y {x^2+y^2} dx$$

- Relevant Equations
- Just math

$$\int \frac y {x^2+y^2} dx$$

$$\frac 1 y * \int \frac 1 {\frac {x^2}{y^2} + 1} dx = \frac 1 y * atan(x/y)$$

The answer is just atan(x/y), which you get using u-substitution but I honestly don't see why I don't get it doing it the normal way.

$$\frac 1 y * \int \frac 1 {\frac {x^2}{y^2} + 1} dx = \frac 1 y * atan(x/y)$$

The answer is just atan(x/y), which you get using u-substitution but I honestly don't see why I don't get it doing it the normal way.