What is the integrating factor of $(1 + x^{2})\frac{dy}{dx} + 2xy = 1$?

Explanation

1. 01

   In the form $\frac{dy}{dx} + Py = Q$, $P = \frac{2 x}{x^{2} + 1}$.

2. 02

   The factor is $e^{\int P\,dx} = x^{2} + 1$.