| t2 | ||
x = | ||
| 2t+1 |
| 2t(2t+1)−2t2 | ||
dx = | dt | |
| (2t+1)2 |
| t2+t | ||
dx = 2 | dt | |
| (2t+1)2 |
| t2 | ||
√x2+x = t− | ||
| 2t+1 |
| t2+t | ||
√x2+x = | ||
| 2t+1 |
| t2+t | t2+t | |||
∫√x2+xdx = ∫ | * 2 | dt | ||
| 2t+1 | (2t+1)2 |
| (t2+t)2 | ||
=2∫ | dt | |
| (2t+1)3 |
| 1 | (4t2+4t)2 | |||
= | ∫ | dt | ||
| 8 | (2t+1)3 |
| 1 | ((4t2+4t+1)−1)2 | |||
= | ∫ | dt | ||
| 8 | (2t+1)3 |
| 1 | ((2t+1)2−1)2 | |||
= | ∫ | dt | ||
| 8 | (2t+1)3 |
| 1 | (2t+1)4−2(2t+1)2+1 | |||
= | ∫ | dt | ||
| 8 | (2t+1)3 |
| 1 | 2 | 1 | ||||
= | (∫(2t+1)dt −∫ | dt+∫ | dt) | |||
| 8 | (2t+1) | (2t+1)3 |
| 1 | 1 | 1 | 1 | ||||
= | ( | (2t+1)2 − ln(2t+1) − | )+C | ||||
| 8 | 4 | 4 | (2t+1)2 |
| 1 | 1 | ((2t+1)4 − 1) | |||
= | ( | − ln(2t+1)) + C | |||
| 8 | 4 | (2t+1)2 |
| 1 | 1 | (4t2+4t+2)(4t2+4t) | |||
= | ( | − ln(2t+1)) + C | |||
| 8 | 4 | (2t+1)(2t+1) |
| 1 | (2t2+2t+1)(t2+t) | |||
= | (2 | − ln(2t+1)) + C | ||
| 8 | (2t+1)(2t+1) |
| 1 | 2t2+2t+1 | t2+1 | ||||
= | (2 | * | − ln(2t+1)) + C | |||
| 8 | 2t+1 | 2t+1 |
| 1 | ||
= | (2(2x+1)√x2+x − ln(2x+1+2√x2+x)) + C | |
| 8 |
| 1 | 1 | |||
= | (2x+1)√x2+x − | ln(2x+1+2√x2+x) + C | ||
| 4 | 8 |