Musiałam narysować, bo było nieczytelne. Jak to ruszyć? coś przez części, ale nwm co podstawić
z u i v
| x2 sinx | ||
∫ | dx = ... Całkowanie przez podstawienie : | |
| cos3x |
| 1 | ||
| t = tgx , dt = | , x = arctgt | | |
| cos2x |
| 2arctgt | ||
|f(t) = (arctgt)2 , f'(t) = | | | |
| t2 + 1 |
| 1 | ||
|g'(t) = t , g(t) = | t2 | | |
| 2 |
| 1 | t2 | |||
... = | t2 (arctgt)2 − ∫ | * arctgt dt = | ||
| 2 | t2 + 1 |
| 1 | t2 + 1 | 1 | ||||
= | t2 (arctgt)2 − [ ∫ | arctgt dt − ∫ | arctgt dt ] = ... | |||
| 2 | t2 + 1 | t2 + 1 |
| 1 | 1 | 1 | ||||
... = | t2 (arctgt)2 − t arctgt + | log(t2 + 1) + | (arctgt)2 + C = | |||
| 2 | 2 | 2 |
| 1 | 1 | 1 | ||||
= | tgx2 (x)2 − xtgx + | log(tg2x + 1) + | (x)2 + C = | |||
| 2 | 2 | 2 |
| 1 | 1 | |||
= | x2( | ) − x tgx − log(cosx) + C | ||
| 2 | cos2x |