Transforms And Partial Differential Equations: UNIT I: Partial Differential Equations: Examples
R.H.S= sin (ax + by) or cos (ax + by)
Replace D2 by -a2,
DD' by -ab, D/2 by -b2
Formulae
Example
1.5.19: Solve [D2 - 2DD' + 2D'2] z = sin (x − y).
Solution:
Given [D2 - 2DD' + 2D'2] z = sin (x -- y)
The auxiliary equation is m2
- 2m + 2 = 0
[Replace D m and D' by 1]
Example
1.5.20 : Solve [D3 - 4D2 D' + 4DD'2] z = 6 sin (3x+6y).
Solution:
Given: [D3 – 4D2 D′ + 4DD'2] z = 6 sin (3x + 6y)
The auxiliary equation is m3
- 4m2 + 4m
Example
1.5.21 : Solve [D2 - 2DD' + D'2] z = cos (x-3y).
Solution:
Given: [D2 - 2DD' + D'2]z = cos (x - 3y)
The auxiliary equation is m2
- 2m + 1 = 0
(m − 1)2 = 0
m = 1, 1
Replace D2 by −12=-1
| DD' by −(1) (−3) =3 D'2 by -(-3)2
= −9
Example 1.5.23: Solve [D2 - 3DD' + 2D'2] z=
sin x cos y
Solution :
Given: [D2 - 3DD' + 2D'2]
z= sin x cos y
The auxiliary equation is m2 - 3m +
2 = 0
M = 1, 2
Example
1.5.24: Solve (D2 - DD') 7- sin x sin 2y
Solution:
Given: (D2 - DD') 7- sin x sin 2y
The auxiliary equation is
Transforms And Partial Differential Equations: UNIT I: Partial Differential Equations : Tag: : Formulae - Examples
Transforms and Partial Differential Equations
MA3351 3rd semester civil, Mechanical Dept | 2021 Regulation | 3rd Semester Mechanical Dept 2021 Regulation