Приклад.
x t 2
2 x 3 2 t 2 3
2 dx dx dt 2 dt
x x4 9 t 2 4 t 2 9
t x 2
2t 1 2t 1
2 dt 2 dt 2 dt
t 5 t 5 t 5
1 t
ln 5t 2 arctg C
5 5
1 x 2
ln x 2 4x 9 arctg . C
5 5