xdx | ||
∫ | ||
√x2+x+1 |
t2−1 | ||
x= | ||
2t+1 |
2t2+t−t2+1 | t2+t+1 | |||
t−x= | = | |||
2t+1 | 2t+1 |
2t(2t+1)−2(t2−1) | ||
dx= | dt | |
(2t+1)2 |
2t2+2t+2 | ||
dx= | dt | |
(2t+1)2 |
t2−1 | 2t+1 | 2(t2+t+1) | ||
∫ | dt | |||
2t+1 | t2+t+1 | (2t+1)2 |
1 | 4t2−4 | |||
= | ∫ | dt | ||
2 | (2t+1)2 |
1 | 4t2+4t+1−4t−5 | |||
= | ∫ | dt | ||
2 | 4t2+4t+1 |
1 | −4t−2 | −3 | ||||
= | (∫dt+∫ | dt+∫ | dt) | |||
2 | (2t+1)2 | (2t+1)2 |
1 | 1 | 3 | 1 | ||||
= | ( | (2t+1)−ln|2t+1|+ | ) | ||||
2 | 2 | 2 | 2t+1 |
1 | 3 | |||
= | ((2t+1)+ | −2ln|2t+1|)+C | ||
4 | 2t+1 |
1 | 2t2+2t+2 | |||
= | ( | −ln|2t+1|)+C | ||
2 | 2t+1 |
1 | ||
= | (2√x2+x+1−ln|2x+1+2√x2+x+1|)+C | |
2 |