| dx | |
=et | |
| dt |
| dt | |
=e−t | |
| dx |
| dy | dy | dt | ||
= | ||||
| dx | dt | dx |
| dy | dy | ||
= | e−t | ||
| dx | dt |
| d2y | d | dy | |||
= | ( | e−t) | |||
| dx2 | dx | dt |
| d2y | d | dy | dt | ||||
= | ( | e−t) | |||||
| dx2 | dt | dt | dx |
| d2y | d | dy | |||
= | ( | e−t)e−t | |||
| dx2 | dt | dt |
| d2y | d2y | dy | |||
=( | e−t− | e−t)e−t | |||
| dx2 | dt2 | dt |
| d2y | d2y | dy | |||
=e−2t( | − | ) | |||
| dx2 | dt2 | dt |
| d2y | dy | dy | |||
− | −2 | +2y=te5t | |||
| dt2 | dt | dt |
| d2y | dy | ||
−3 | +2yte5t | ||
| dt2 | dt |
| x3 | x3 | 1 | ||||
u(x)= | lnx−∫ | * | dx | |||
| 3 | 3 | x |
| x3 | 1 | |||
u(x)= | lnx− | ∫x2dx | ||
| 3 | 3 |
| x3 | 1 | |||
u(x)= | lnx− | x3+C | ||
| 3 | 9 |
| 1 | ||
u(x)= | x3(3ln|x|−1)+C | |
| 9 |
| 1 | 1 | x4 | 3 | ||||
∫u(x)= | x4(3ln|x|−1)− | ∫ | dx+C1x | ||||
| 36 | 9 | 4 | x |
| 1 | 1 | |||
∫u(x)= | x4(3ln|x|−1)− | ∫x3dx+C1x | ||
| 36 | 12 |
| 1 | 1 | |||
∫u(x)= | x4(3ln|x|−1)− | x4+C2+C1x | ||
| 36 | 48 |
| 1 | ||
∫u(x)= | x4(12ln|x|−4−3)+C2+C1x | |
| 144 |
| 1 | ||
∫u(x)= | x4(12ln|x|−7)+C2+C1x | |
| 144 |
| 1 | ||
y(x)=x( | x4(12ln|x|−7)+C2+C1x) | |
| 144 |
| 1 | ||
y(x)= | x5(12ln|x|−7)+C1x2+C2x | |
| 144 |