0% found this document useful (0 votes)
99 views19 pages

M2 Unit 2 QB

1. The document provides solutions to various differential equations using methods like finding the complementary function, particular integral, auxiliary equation method, and variation of parameters. 2. Key steps include setting up the auxiliary equation, finding the roots to determine the complementary function, and using an integrating factor or variation of parameters to find the particular integral. 3. Examples solved include equations of the form (D^n + aD^m + ...)= f(x), with f(x) being functions like sinx, cosx, e^x, etc. Initial/boundary conditions are also specified to get the full solution.

Uploaded by

Mvk Mvk
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
0% found this document useful (0 votes)
99 views19 pages

M2 Unit 2 QB

1. The document provides solutions to various differential equations using methods like finding the complementary function, particular integral, auxiliary equation method, and variation of parameters. 2. Key steps include setting up the auxiliary equation, finding the roots to determine the complementary function, and using an integrating factor or variation of parameters to find the particular integral. 3. Examples solved include equations of the form (D^n + aD^m + ...)= f(x), with f(x) being functions like sinx, cosx, e^x, etc. Initial/boundary conditions are also specified to get the full solution.

Uploaded by

Mvk Mvk
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
You are on page 1/ 19

Maths uestion Ban

Unit-2
Find the Comple mentaiy fun ction of CD3+1 y COSax
(b+1)y Cvsa

So y- CF
auxilay equation 15 Fm):u

m+ o

C a t b3 = (atb) lat-abt b)

(mt) (m-m+) =b
m -1 m-mtl=0

m 1t1-4

m:13 . Ni

CF CE"+ (C,tos C3 Sin x) e


a Solve b-3D°-3D+4D+4y=o

D-D -3D2+u Dt 4)y=O


auzilany equation is flm)=o

Cm- am-3 m +4m+4)y =o


m am' - 3m +sm +4 =0

:-1 1S bne YOot

|I -3

m O 1 3 -
-3 O
m-3m+ 4 M =O

m: - IS anbthey YOot
3 0 4
m- -14- 4

m- ym t4 0 (m-2)- o
Cm-a) tm-3) o
m ,

m-1, -1, 2,2


Solution: y>CF
y (Ci+C a)e* + CC3t Cua)e*

3 Solve lD3- 5D+8D-4) y-b


(D- 5D+ 8 D- 4)y=o
auailary equation is Plm) =o
m 5m+8m-4 =
m= is one TOOt

5 8 - L

m
4
-4 4
m-4m +4 o - m-a)'-o
m-2) (m-2) = d

m , 2,3

Solution: y: CF

y C1e*+ CC2t C3) e2


( D + 2z^D+2)y =o

(3p3 a2' D'+a)y0-0


et ea 0 is in the foim DP Cauchys Euler diffevential

equat10n

tet 2D =6 , D°- el0-1), *3p- ole-1) l -)


wheve e=> e-> tog = 2

o(o-1)te-a) + 20 (0-1) +2)y =


(e o3042) + 20- 20+2)y=6
(o3-30'+26 + 2o6+ 2)y=o
(3-0+a)y-0
auxilay equation is f(m)-o

m-m+3 = O
m-I is one oot

|1- 1 D
m--1 -1:
2 2 o

m- a m +3=D

m 2 t J4- 4l)t2)

m a tJ-4 1i

m:1, t i

Solution y= CP
y Ce+ (C, Co5 2+ C38inz) ez
CC2 Cos (Loga) + C3 Sirnt toga)*
5 Find the complementa9 Functi on df D+1Dy= osan
Refer No
Solve2Dt3 Sin
Sin
D43
D-3
Sin
(D+3) (D-3)

D-3 - Sinx

D-9
put D
D3sina D(sinx)
-1-9 -D

DCOSX- 3sin)

Find the solution of the dif Pevential equati on tD'+4)y=o

Qunilay equation is fim)=b

m -4
m t-4
m: tai

Soluti on y= CCF

y CC Cos aGSinax)e
8 Solve (a*D* - 4 D + 6)y=0

(xD-yzD4C)y=o-0
ea o i s in the foim of Cauthy's Euley dlifPeventi al
equation

et D e, D?= ©lo-1)

where e=> Log 2

(ete-1)- 40+6)y=o
(e2--496) y=0
e2-50+6)y- o
auilary equation is flm)=0

m-SmtG D

m-am-3mt G op
mm-2)-3( m-a)=o

Cm-3) (m-3)
m 2, 3
Solution y: CF

CD45Dt c)y = e
Solve
D 4 SD +6) y = e

flm)=b
auxilary equation is
m t 5 m tG = D

m+am+3m + 6 =0
mtmta) +3(m-+3)=0

Cm+a) (m+3)=O
m: 2 , -3

CF = CIe Ca

PI e
D4 5D+4G
put D

e
1+5tG

ID Solve d-=0
A-20
dt3

iven d =0 -

0
d3

eq O in operatoY fom is

(p3-1) O
auxilay equation is fm)=O

m- o a3b3 =
(0-b) (a?4 abt b'))
(m-1) m*+m+1) = D

m mtmt1 =O
- ItN1-4 t3

m-,1ENei
Solution y C 72

Cie+ (C, (os a t Czsin 3z


)e
I1 Find particulay int cqral Df (D6- pu) = **

(D-D4 ) x2 -D

PI .

D-D4

-D+D6 -D+ (1-D°)

1-DSa
D+

(1-D I+ D+D'4.
-

+D) *2
D4
L'+a)
D4

(7*)
()
PART-B
Solue - a t39 =e"tan by method of waiation
dz2
PaYameters.

d 2 + y e tan -0
d
P2 Q 2 R= etan
form is
ea Din opeiatoDY
(D 2D+ 2) y e tan -
1S ftm )= O
Auilay equation
m-am + =D

m- u-B

m tN-4 1ti

CF =(Ci COS
+ C Sin ) e

CF Aua) +8v(1) Ciuc)t C V(X)


ula)= CoS eX V(x) Sinxc*
u'(a) COSX e+-eX sin
e(CoS -Sinx)

V'a) = Sinz e" + e coSX


=e COSx tsina)
2
uv'-vu' =e ? CoSX( Coszt Sinx)-e Sin Cosx- sin)

= ea(cos'1+ (oSz6in
-

Cosx sAnz 4sin'a)

l T PI AutX)t Bv(x)

sin eM. tan-


A-VR
d dz

Juv'-vul

sin'2 d CoS d
CoS
CoS COS

-CseCz- COS ) dx
Logl se ( a t tana]-sìn
sin- Jog] Se ca4 tan2

B uR Ce tosz 2 tan
d
Uv'-vu e

sind di - (DS :

Au(a) CoS2 e^ Sinz - tOS e , Logl Set t tana

Bvx) -

e tosx4S i n
Solution y: CF P I
cog|secxttanx|
e Cos sihx (oS
-

y (CicoSx + (, Sinx)et
+

- eYtoy'a Sifx

(C COSx C2sinx) e CoS ae. Jog| Secttana

a. Solve CD4-1)y =e" cos


D-1) y el cosx
cquation is f(m)=O
auxilay

C a-b- (atb)(a-b))
(m41) m-1) - 0

m-ti

CF (Ci CoS + ( Sinx) + C3 e+ Cue

P:I e ws
D4-1

put D= Dt

e -oS
(D+I

e CoS
D 4D3+ 6DH4 DM

e - COSX

b 4D + GD+ 4D
put D' -I

e COSX
-+u-1)-64 46
e COS
1-G
,
CDS

Solution y: (Ci
CoSX 4 (Sina) + C3e4 Ce*- osz
by the method dF vaTiatiDn of
3 Solve CD41Dy COSeCxx
Paramete1s
CD41Dy COSeC -0

Auxilay cquation is f(m)-b

m tN

CE C CoS X + (> sinx


CF C u(a) t C> V(A)

uta = COS vUa)= Sinx


u'(a -Sinx v'()= CoS

uv-vu = CoSx+ Sin

lbT PI A u (a) t BV(A)

A -VR Sinx CDSec


-d
Juv-vul

-sirh dz
Sip
-X

uR
dd cosx Cosecz d
uv'vu

(CoS d
Sin
tDgIsinx |
Solution y CF +PL

U: C CoS7 t C2 Sind - LoS+ log1Sinx |Sin


4Solve (D2-y0tu)y 8x esina
Giiven (DuD 4)y-8x csinax -DD
auxilay cquation is f (m) =
O

m - u m +u D

(m-2)- 0

(m-a) tm-2)-0
m- ,

CFCC t (,%)c?

PI 8e2 ? sin a
D-y D+u

put D D+2

82 Sin 2
CD+2) y(D+2)+

8e2 Sin 2x

8e27 - Sin 2
D2

isina2
e2 COs27+
is the I P of el2
Sin 32

8e IP of ei3
put D Dt3i

8e37 P of ei2
D+2i

8e IP of elD_
D1 4Di-4

8e
9 IP of eld *
y4Di4D
- 8ee IP of el3x
el 1
-8
ul-(Di+ R)
-a P of ei2(1-(Di+
C1-D l+D + D+ -

2c 1P of e13 (14 CDit ) + (Di+ ) ) x

- 22 IP of ei32 ( + ai+-2)
- e IP of e ( (3)+2%i)
-a2 TP of (tos 32 t isinaa( a2-3)+ 2ai)
-
2 e27(a2cos32 t Sinax (**-
Solution: y= CF +PI

y C C t C2x ) e - a2 (3 Cos ax + 5inaz (*-))

5 Solve D-5Dt 6) y= e *

iven CD2-5Dt 6)y- *e -0

auxilay equation is ftm) D

m-5m +6 =0
m-2 -3m+ 6= D

m (m-)-3(m-2)=0
m-3) (m-3)= O

m- , 3

CF C e?x 4 Cze3*

P.T D5D G -

Cput D = D+1)

e
(D+I-50+4)+6
eX
D++D-5D-5+6
D+I42D-5p++
e
D3D + 2
3D+ D?

2(1-3D+D)

(1-3D4D)-
-D'= 1+D+ D4

1-3D D )
-ap )
-34to)

Solution y= CF+PI

6 Solve the differential equation (D-5Dt 6)y eSina

D-5D+ 6)y e sin - D

Auilary equation is flm)-o


m-5m + 6 0
m- am -3m+ 6=D

mm-2)-3(m-)=0
Cm-a) (m-3)=o
m: 2, 3

CF Ce 27 + C, e3
PT e sin
D-5D
put D= Dt

e Sin
CD+1-5lD+1D+6
Sio
D4142D -5D-St6
Put D 1
Sin
e
-14-3D+1
Sin
3D

e 3D _Sin
1-902

Put D-

(143D) Sina
ex (Sin +3 (oSa)

T0
SOlution :y-(F+ PI
Cie+Ca¬*4 sinz43 COS
=*e°-Sin243
(D2Dt)y
diffeventiai cquation
SOve the

Gilven (D-a0+)y-0
is flm)=0
AulilaYy equation

m2-am+)y-0
m2-am+1=0

(m-1)- o
m-1)(m -1)=0

m ,
CF CI C22) e^
( )
P.l Put D D+3
-2D+1
3
2

CD+3-a (D+3)+1

e
3 1 2 Q2

D4946D- aD- 6tl

3X

4 +4D4 D2
3

4(14 D+)
(14D) 1-D+D".
3*

(1D-p)x
4
3X

4 (- +a) (2+)
PI - Sinox
D-2D+1
put D -

Sina sin2S
-44D+J -D-3

2D-3)
4D-9
sina
put D- -4

( D-3) sinox)
95

(
5
3D-3) Sin 2x 4 CDS 37 -3sin 9 )

P I3 3e
D Dt1 put D O

3 e

3
Solution y: CF+ PI1t PI, + PI3

CC+ Cx)e^+ e ( 7+ 3 ) - (y tosax 3sin3*) +3


y
L
diffevential equation
8 Solve the

(x3D 3x'D+a)y 1o[


1ox
i v en (*D4 3aa'D'+ ay
aiffevential equation
Cauthys tulcY
WB:T eq D is
D(O-1) 3Dol0-1) t0-a)
tet D O D
e
whee

oe-1)(0-2)+ 2olD-1)+ 3)y 1Det loe

ote-30+ 9) + 20- 394 3 )y loe tIDe


(33e461 3e?-a6+a)y= toe+1oëz
te3e'+ 2)y- 10e+ tDeZ
auxilay equation is flm) D

m-1 is one oot

m-D 2

m-am+ a =0

m3tNu-41)3) 9t -s

m: -I, 11

CF C e t CC2 Cos 2 + C2 Sin2)e

PI IDe
+2

put 1

e2 Se2
A+2
PI De

put -I

1-1

Case of failure

t02 2
302- 20
Put e -1

I02
32 102 5

Sotution y CF+PI+ PI
: Cie+ CC CDS24 C3 sin2) e+ 5e'+ 92ë

+ CCa CoS Cogu)+ C3Sin (log1) *+ 5 + 2 Jog2

9 Solved,- 3 + 2y 37
aetSin 2x
3
Given dy a dy 4 ay e°*+Sin 3aO
dr
e D in operoutDY fom is

CD 3D42)y e?*+ Sin 2


auxila1y equation is flm)= o

(m2m 49) y=0


m-3m+ 3 =0
m-9mn -m+3=O

m (m-) -1 (m-)=D
(m-3) m-1) =u

CF Ce + C, e2
0 SOlve (142) d'y + ( t ) + 9 2sin (10q (4))
d
Gnven (14 d'y + H) dY +y= 2Sin ( loq tHa)) ->0
da2 da

in opevato fovm is
eq.o

(1470 D+ (47)Dt Dy- 2Sin


(1og lI42))->
.K.T eq-2 is tleqencse's equation

let14a)D = e (I402= e (B-1)


(42) = z
where 1+ e lq
2Sinz
(e (e-1)+ 0+1)y -

-++)y= 2Sinz

(+)y 2Sinz

f(m) = 0
auxilary Equation is
m + l = OD

m-1
m= ti

CF C COs z + C2. Sin z


2sinz
P-I=
e2+1
Pt e
2 Sinz
-1+1
Case of faüluve

2sin z
zOS Z

SOIution: y= CF+ PI
C2Sin z - z o sz
-CCCSZ t

y= C0S tLogt+) + Ca Sin (Dgi+) - Log C1+2) Cos(Log tl47))


1-Solve CD-4D +3 y Sin3X cos3
D- 4p+ 3) y sin3a Cos ax -0

auila7y equation is +m)=0

m-3m - mt3-O
mtm-3)-1( m-3)=O
(m-3) tm-1)= d
m 1,3
CFCie%+ 3

P-I s i n 3 CoS ax
D p+3
sin3xa (Sin3x cos ax)
D- y D+3

C sinACo$B = Sin (At B) Sin lA-B))

D24D+3
Sinsz +sin )
D 4D+3
P I Sin5
D4D+3
put D -

25

- 25-4D+3
Sin5 ) SinSx
-4 D-22

aD- sin5
4D-121
put D- -25

- aD- sins (s Io CosS- |sinsa)


-ID0-12 884

a 1OoS5x- 11sin5)
884
sin
PT 2 D4P43
put D -I
Sin Sin
-1 -s-Dt4 3 -4D+2
Sinx
21-aD
142D SInx
-4D
Put D= -J
H 3 D J4aD sin S ina t 2 CoSa)
2
14 4
Solution y= CF+ PI +PI2
y Cie+ C e3%+ 88 4
(toCosSX - 11sin5a)t sinx t 200Sx)

You might also like