1 | ||
Oblicz całke ∫ | dx | |
x4√x2+1 |
1 | 1 | 1 | 1 | t3 | ||||||
∫ | = [t = | , x = | , dx = − | dt] = −∫ | dt = | |||||
x4√x2 + 1 | x | t | t2 | √t2 + 1 |
1 | u − 1 | |||
= [u = t2 + 1, du = 2tdt, dt ] = − | ∫ | du = | ||
2 | √u |
1 | 1 | |||
= − | (∫√udu − ∫ | du) = ... | ||
2 | √u |
2t | ||
x = | ||
1−t2 |
2t2 | ||
xt+1 = | +1 | |
1−t2 |
2t2+1−t2 | ||
xt+1 = | ||
1−t2 |
1+t2 | ||
xt+1 = | ||
1−t2 |
2(1−t2)−2t(−2t) | ||
dx = | dt | |
(1−t2)2 |
2 − 2t2 + 4t2 | ||
dx = | dt | |
(1−t2)2 |
2+2t2 | ||
dx = | dt | |
(1−t2)2 |
2(1+t2) | ||
dx = | dt | |
(1−t2)2 |
1 | (1−t2)4 | 1−t2 | 2(1+t2) | |||
∫ | dx = ∫ | dt | ||||
x4√x2+1 | 16t4 | 1+t2 | (1−t2)2 |
1 | (1−t2)3 | |||
= | ∫ | dt | ||
8 | t4 |
1 | 1 | 3 | ||||
= | ∫( | − | + 3 − t2) | |||
8 | t4 | t2 |
1 | ||
= | (∫t−4dt−3∫t−2dt + 3∫dt − ∫t2dt) | |
8 |
1 | 1 | 1 | 1 | 1 | 1 | |||||
= | (− | + | +3t − | t3)+C | ||||||
8 | 3 | t3 | 3 | t | 3 |
1 | 1 | 1 | 1 | |||||
= | (− | (t3+ | ) + 3(t+ | ))+C | ||||
8 | 3 | t3 | t |
1 | 1 | 1 | ||||
=− | ((t3+ | ) − 9(t+ | ))+C | |||
24 | t3 | t |
1 | 1 | 1 | 1 | |||||
=− | ((t3+ | ) +3(t+ | )− 12(t+ | ))+C | ||||
24 | t3 | t | t |
1 | 1 | 1 | ||||
=− | ((t+ | )3 − 12(t+ | ))+C | |||
24 | t | t |
1 | (t2+1)3 | 1 | t2+1 | |||
=− | + | +C | ||||
24 | t3 | 2 | t |
1 | (t2+1)3 | t2+1 | |||
=− | + | +C | |||
3 | (2t)3 | 2t |
2t | ||
x = | ||
1−t2 |
1+t2 | ||
√x2+1 = | ||
1−t2 |
t2+1 | 1+t2 | 1−t2 | |||
= | * | ||||
2t | 1−t2 | 2t |
t2+1 | √x2+1 | ||
= | |||
2t | x |
1 | √x2+1 | √x2+1 | ||||
= − | ( | )3 + | + C | |||
3 | x | x |
(x2+1)√x2+1 | 3x2√x2+1 | |||
=− | + | +C | ||
3x3 | 3x3 |
(3x2−x2−1)√x2+1 | ||
= | +C | |
3x3 |
(2x2−1)√x2+1 | ||
= | +C | |
3x3 |
1 | 1+x2−x2 | |||
∫ | dx = ∫ | dx | ||
x4√x2+1 | x4√x2+1 |
1 | √x2+1 | 1 | ||||
∫ | dx =∫ | dx − ∫ | dx | |||
x4√x2+1 | x4 | x2√x2+1 |
√x2+1 | 1 | |||
∫ | dx − ∫ | dx = | ||
x4 | x2√x2+1 |
√x2+1 | 1 | x | 1 | |||||
− | − ∫(− | )( | )dx− ∫ | dx | ||||
3x3 | 3x3 | √x2+1 | x2√x2+1 |
√x2+1 | 1 | |||
∫ | dx − ∫ | dx = | ||
x4 | x2√x2+1 |
√x2+1 | 1 | 1 | 1 | |||||
− | + | ∫ | dx− ∫ | dx | ||||
3x3 | 3 | x2√x2+1 | x2√x2+1 |
√x2+1 | 1 | √x2+1 | 2 | 1 | ||||||
∫ | dx − ∫ | dx =− | − | ∫ | dx | |||||
x4 | x2√x2+1 | 3x3 | 3 | x2√x2+1 |
1 | 1+x2−x2 | |||
∫ | dx = ∫ | dx | ||
x2√x2+1 | x2√x2+1 |
1 | √x2+1 | 1 | ||||
∫ | dx = ∫ | dx − ∫ | dx | |||
x2√x2+1 | x2 | √x2+1 |
1 | √x2+1 | 1 | x | 1 | ||||||
∫ | dx = − | − ∫(− | )( | )dx − ∫ | dx | |||||
x2√x2+1 | x | x | √x2+1 | √x2+1 |
1 | √x2+1 | 1 | 1 | |||||
∫ | dx = − | +∫ | dx−∫ | dx | ||||
x2√x2+1 | x | √x2+1 | √x2+1 |
1 | √x2+1 | |||
∫ | dx = − | |||
x2√x2+1 | x |
1 | √x2+1 | 2 | √x2+1 | |||||
∫ | dx =− | − | (− | )+C | ||||
x4√x2+1 | 3x3 | 3 | x |
1 | √x2+1 | 2 | √x2+1 | |||||
∫ | dx =− | + | ( | )+C | ||||
x4√x2+1 | 3x3 | 3 | x |
1 | (2x2−1)√x2+1 | |||
∫ | dx = | + C | ||
x4√x2+1 | 3x3 |