Unit - 6
Solution of Ordinary Differential Equation (ODE)
Q1) Solve, using Taylor’s series method and compute .
A1)
Here This implies that .
Differentiating, we get
.
.
.
The Taylor’s series at ,
(1)
At in equation (1) we get
At in equation (1) we get
Q2) Using Taylor’s series method, find the solution of
At ?
A2)
Here
At implies that or or
Differentiating, we get
implies that or .
implies that or
implies that or
implies that or
The Taylor’s series at ,
(1)
At in equation (1) we get
At in equation (1) we get
Q3) Use Euler’s method to find y(0.4) from the differential equation
with h=0.1
A3)
Given equation
Here
We break the interval in four steps.
So that
By Euler’s formula
, n=0,1,2,3 ……(i)
For n=0 in equation (i) we get
For n=1 in equation (i) we get
.01
For n=2 in equation (i) we get
For n=3 in equation (i) we get
Hence y(0.4) =1.061106.
Q4) Given with the initial condition y=1 at x=0. Find y for x=0.1 by Euler’s method (five steps).
A4)
Given equation is
Here
No. Of steps n=5 and so that
So that
Also
By Euler’s formula
, n=0,1,2,3,4 ……(i)
For n=0 in equation (i) we get
For n=1 in equation (i) we get
For n=2 in equation (i) we get
For n=3 in equation (i) we get
For n=4 in equation (i) we get
Hence
Q5) Use modified Euler’s method to compute y for x=0.05. Given that
A5)
Result correct to three decimal places.
Given equation
Here
Take h = = 0.05
By modified Euler’s formula the initial iteration is
)
The iteration formula by modified Euler’s method is
-----(i)
For n=0 in equation (i) we get
Where and as above
For n=1 in equation (i) we get
For n=3 in equation (i) we get
Since third and fourth approximation are equal.
Hence y=1.0526 at x = 0.05 correct to three decimal places.
Q6) Using modified Euler’s method, obtain a solution of the equation
A6)
Given equation
Here
By modified Euler’s formula the initial iteration is
The iteration formula by modified Euler’s method is
-----(i)
For n=0 in equation (i) we get
Where and as above
For n=1 in equation (i) we get
For n=2 in equation (i) we get
For n=3 in equation (i) we get
Since third and fourth approximation are equal.
Hence y=0.0952 at x=0.1
To calculate the value of at x=0.2
By modified Euler’s formula the initial iteration is
The iteration formula by modified Euler’s method is
-----(ii)
For n=0 in equation (ii) we get
1814
For n=1 in equation (ii) we get
1814
Since first and second approximation are equal.
Hence y = 0.1814 at x=0.2
To calculate the value of at x=0.3
By modified Euler’s formula the initial iteration is
The iteration formula by modified Euler’s method is
-----(iii)
For n=0 in equation (iii) we get
For n=1 in equation (iii) we get
For n=2 in equation (iii) we get
For n=3 in equation (iii) we get
Since third and fourth approximation are same.
Hence y = 0.25936 at x = 0.3
Q7) Use Runge Kutta method to find y when x=1.2 in step of h=0.1 given that
A7)
Given equation
Here
Also
By Runge Kutta formula for first interval
Again
A fourth order Runge Kutta formula:
To find y at
A fourth order Runge Kutta formula:
Q8) Using Runge Kutta method of order four, solve to find
A8)
Given second order differential equation is
Let then above equation reduces to
Or
(say)
Or .
By Runge Kutta Method we have
A fourth order Runge Kutta formula:
Q9) Use Jacobi’s method to solve the system of equations:
A9)
Since
So, we express the unknown with large coefficient in terms of other coefficients.
(1)
Let the initial approximation be
2.35606
0.91666
1.932936
0.831912
3.016873
1.969654
3.010217
1.986010
1.988631
0.915055
1.986532
0.911609
1.985792
0.911547
1.98576
0.911698
Since the approximation in ninth and tenth iteration is same up to three decimal places, hence the solution of the given equations is
Q10) Use Jacobi’s method to solve the system of the equations
A10)
Rewrite the given equations
Let the initial approximation be
1.2
1.3
0.9
1.03
0.9946
0.9934
1.0015
Hence the solution of the above equation correct to two decimal places is
Q11) Solve the following system of equations
By Gauss-Seidel method.
A11)
Rewrite the given system of equations as
Let the initial approximation be
Thus the required solution is