| 1 | ||
∫∞ 0 | dx | |
| x2+2x+5 |
| 1 | ||
∫0−∞ | dx | |
| 2x2+8x+10 |
| (x+1)2 | x+1 | |||
x2+2x+5 = (x+1)2+4 = 4*[ | + 1] = 4*[ ( | )2 + 1 ] | ||
| 4 | 2 |
| x+1 | ||
t = | ||
| 2 |
| dx | ||
dt = | ||
| 2 |
| 1 | x+1 | |||
J1=8∫ | dt = 8arctgt + C = 8arctg | +C | ||
| t2+1 | 2 |
| x+1 | ||
= lima→∞ [ 8arctg | 0]a = | |
| 2 |
| a+1 | 1 | π | 1 | |||||
lima→∞ [ 8arctg | − 8arctg | ] = 8[ | − arctg | ] | ||||
| 2 | 2 | 2 | 2 |
| dx | 1 | dx | ||||
2)∫ | = | ∫ | = | |||
| 2x2+8x+10 | 2 | x2+4x+5 |
| 1 | dx | ||
∫ | = ... | ||
| 2 | (x+2)2+1 |
| 1 | dx | 1 | ||||
...= | ∫ | = | arctgt= | |||
| 2 | t2+1 | 2 |
| 1 | ||
= | arctg(x+2)+C | |
| 2 |