| 1 | ||
∫ xtgx | dx | |
| cos2x |
| 1 | ||
dt = | dx | |
| cos2x |
| 1 | dx | |||
∫ x tgx | dx = | tgx=t ⇒ | =dt i x=arctgt | = ∫ t arctgt dt = | ||
| cos2x | cos2x |
| dt | ||
= | u=arctgt i dv= t dt ⇒ du= | i v= ∫ t dt= 12t2 |= | |
| 1+t2 |
| t2 | ||
= 12t2 arctgt − 12 ∫ | dt = | |
| 1+t2 |
| 1+t2−1 | ||
= 12t2 arctgt − 12 ∫ | dt = ... i dalej spróbuj sam . ... | |
| 1+t2 |