Solve ( x 2 − y 2) d x 2 x y d y = 0 I'm asked to solve it using 2 different methods I proved I can find integrating factors of type μ 1 ( x) and μ 2 ( y / x) If I'm not wrong, these two integrating factors are μ 1 ( x) = x − 2 , μ 2 ( y / x) = ( 1 y 2 x 2) − 2 ∂ ψ ∂ x = x − 2 (