Janek191:
x
2 − 4 = (x − 2)*(x + 2)
1 | | A | | B | |
| = |
| + |
| / *( x − 2)*(x + 2) |
(x −2)*(x + 2) | | x −2 | | x + 2 | |
1 = ( x + 2)*A + ( x − 2)*B
1 = A x + 2 A + B x − 2 B = ( A + B) x + ( 2 A − 2 B)
więc
A + B = 0 / * 2
2 A − 2 B = 1
−−−−−−−− dodajemy stronami
4 A = 1 ⇒ A = 0,25
B = − A = − 0,25
czyli
| dx | | 0,25 | | −0,25 | |
∫ |
| = ∫( |
| + |
| )dx = 0,25 ln I x −2 I − 0,25 ln I x +2 I +C |
| x2 −4 | | x −2 | | x +2 | |