Probability and complex function: Unit V: Differential equations: 1. (e) problems based on R.H.S = xn : Examples
1. (e) PROBLEMS BASED ON
R.H.S = xn
Note:
The following formulae are important.
(1
+ x)-1 = 1 – x + x2 – x3 + …
(1
+ x)-1 = 1 + x + x2 + x3 + …
(1
+ x)-2 = 1 – 2x + 3x2 – 4x3 + …
(1
+ x)-2 = 1 – 2x + 3x2 + 4x3 + …
Example
5.1.30. Solve d2y / dx2 - 5
dy/dx + 6y = x2 + 3.
Solution
:
Given
: d2y / dx2 - 5 dy/dx + 6y = x2 + 3.
i.e.,
(D2 - 5D+6) y = x2 + 3
The
auxiliary equation is m2 - 5m + 6 = 0
⇒ m = 3, m = 2
Example
5.1.31 Solve (D2 - D) y = x
Solution:
Given
(D2 - D) y = x
The
auxiliary equation is m2 – 1 = 0
m2
= 1
m
= ± 1
Example
5.1.31 Solve (D2 - D) y = x
i.e, d2y / dx2 – dy / dx = x
Solution:
Given
(D2 - D) y = x
The
auxiliary equation is m2 – m = 0
m(m
– 1) = 0
⇒ m = 0, m = 1
Example
5.1.33. Solve (D3 - 3D2 - 6D+8) y = x
Solution:
Given: (D3 - 3D2 - 6D+8) y = x
The
auxiliary equation is (m3 - 3m2 - 6m+8) = 0
⇒ m = 1, m = -2, m = 4
Example
5.1.34. Solve [D4 - 2D3 + D2] y = x3.
Solution:
Given: [D4 - 2D3 + D2]
y = x3
The
auxiliary equation is m4 - 2m3 + m2 = 0
m2
(m2 - 2m + 1) = 0
m2
(m - 2m + 1) = 0
m2
(m-1)2 = 0
m
= 0, 0, m = 1, 1
Example
5.1.35. Solve D2 (D2 + 4) y = 96x2
Solution:
Given: D2 (D2 + 4) y = 96x2
The
auxiliary equation is m2 (m2 + 4) = 0
m2
= 0, m2 + 4 = 0,
m
= 0, 0 m = ± 2i
Example
5.1.36. Solve (D3 +8) y = x4 + 2x + 1
Solution:
Given: (D3 +8) y = x4 + 2x + 1
The
auxiliary equation is m3 + 8 = 0
Probability and complex function: Unit V: Ordinary Differential Equations : Tag: : Solved Example Problems | Ordinary Differential Equations - (e) problems based on R.H.S = xn
Probability and complex function
MA3303 3rd Semester EEE Dept | 2021 Regulation | 3rd Semester EEE Dept 2021 Regulation