Całki
Ada: | | arctg x | | 1 | |
∫ |
| |
| dx |
| | √1+x2 | | 1+x2 | |
arctgx = t ⇒ x = tg t ⇒ 1+x
2 = 1+tg
2 t
(arctg x) dx = dt
| | 1 | | 1 | |
∫ |
| dt = ∫ |
| dt = |
| | √1+tg2 t | | | |
| | 1 | | 1 | |
∫ |
| dt = ∫ |
| dt |
| | | | cos2t | | sin2 t | | √ |
| + |
| | | | cos2t | | cos2 t | |
| | | |
=
∫
√cos2t dt = ∫cos t dt = −sin t = −sin(arctg x) +C
25 sty 10:51
kochanus_niepospolitus:
'tyci' problem:
√cos2t ≠ cost
25 sty 10:53