pertemuan 9 persamaan diferensial

PERSAMAAN DIFERENSIAL
Pertemuan 9, PD Bernouli

Nikenasih Binatari
[email protected]

TAKWA, MANDIRI, CENDEKIA

http://fmipa.uny.ac.id

PRESENTATION PARTS
1

2

3

• Review PD Homogen
• Review PD Linear
• PD Bernoulli


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Review PD Homogen
Definisi homogen
A function
of two variables x and y is said
homogeneous if it satisfies
� ,� =
,
for any number t.

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Definition
A function M of two variables x and y is said to be
homogenous of degree-n if it satisfies

� , � = ��
,

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Definition
A first differential equation
,

+

,

=

or

=


,

is called homogeneous differential equation if M
and N are homogeneous functions of the same
degree n or f is a homogenous function.

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Menyelesaikan PD Homogen
PD Homogen (dalam x dan y)
Transform y = vx
PD separabel (dalam v dan x)
Selesaikan PD separabel
Inverse transform v = y/x

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PD Linear
Definition
A first-order ordinary differential equation is linear
in the dependent variable y and the independent
variable x if it is, or can be, written in the form
+

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=

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Menyelesaikan PD Linear
Suppose the integrating factor

= �




The general solution of linear differential equation
as follows
= �−

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+

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PD Bernoulli
Definition
An equation of the form
+

=




is called a Bernoulli differential equation.

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Theorem
Suppose n ≠ 0 or n ≠ 1, then the transformation � =
−� reduces the Bernoulli equation
+

into a linear equation in v.

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=




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Example
Solve the differential equation below

+

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=

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Answer :
To solve the differential equations above, first we
have to divided both side with
. Here we get,


Suppose � =


− �






+

then



��





=−

. By here, we get

+ − �=

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=



or else

��


=


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To solve the equation, we use integrating factor

Then the solution is



=

� = �−

�=

=

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ln

=





+

=

+


=

+

→�=
+





+

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Solve the following differential equations.
.



.

+

.

.

+
+

=

=

=

=

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Referensi :
1. Ross, L. Differential Equations. John Wiley &
Sons.

TAKWA, MANDIRI, CENDEKIA

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THANK YOU
Nikenasih Binatari
[email protected]
Karangmalang Sleman Yogyakarta
TAKWA, MANDIRI, CENDEKIA

http://fmipa.uny.ac.id