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NMLA


Unit – 2


Solution of linear simultaneous Equations

Q1) Apply Gauss Elimination method to solve the equations:

    

A1)

Given                                                    Check Sum (sum of coefficient and constant)

                                     -1                            …. (I)

                                   -16                          …. (ii)

                                       5…. (iii)

(I)We eliminate x from (ii) and (iii)

Apply eq(ii)-eq(i) and eq(iii)-3eq(i) we get

                                             -1                            ….(i)

                                          -15                          ….(iv)

                                       8           ….(v)

(II) We eliminate  y from eq(v)

Apply

                                              -1                            ….(i)

                                          -15                          ….(iv)

                                   73           ….(vi)

(III) Back Substitution we get

                 From (vi) we get

                  From (iv) we get

                   From (i) we get 

Hence the solution of the given equation is

 

Q2) Solve the equation by Gauss Elimination Method:

   
A2)

Given

           

      

      

Rewrite the given equation as

                                   … (i)

                                              ….(ii)

                                               ….(iii)

                                        …(iv)

(I)                We eliminate x from (ii),(iii) and (iv) we get

Apply eq(ii) + 6eq(i), eq(iii) -3eq(i), eq(iv)-5eq(i) we  get

                                       …(i)

                                                     ….(v)

                                               ….(vi)

                                    …(vii)

(II)             We eliminate y   from (vi) and (vii) we get

Apply 3.8 eq(vi)-3.1eq(v) and 3.8eq(vii)+5.5eq(v) we get

                                         …(i)

                                ….(v)

                            …(viii)

                                 …(ix)

(III)           We eliminate z from eq (ix) we get

Apply 9.3eq (ix) + 8.3eq (viii), we get

                                       … (i)

                                ….(v)

                            …(viii)

        350.74u=350.74

       Or u = 1

(IV)          Back Substitution

From eq(viii)

Form eq(v), we get

From eq(i) ,

Hence the solution of the given equation is x=5, y=4, z=-7 and u=1.

 

Q3) Apply Gauss Elimination Method to solve the following system of equation:

     

A3)

Given                    … (i)

                            … (ii)

                            … (iii)

(I)                We eliminate x from (ii) and (iii)

Apply we get

                              … (i)

                            … (iv)

                           … (v)

(II)             We eliminate y from  (v)

Apply we get

                                                       … (i)

                            … (vi)

 

                                                 … (vii)

(III)           Back substitution 

From (vii)  

From (vi)

From (i)

Hence the solution of the equation is

 

Q4) Solve the system by Gauss Elimination method using partial pivoting

                                 

                                   

A4)

Given exact solution is

Given equations are

                                   

Using partial pivoting we rewrite the given equations as

                                      (1)

                                   (2)

Using Gauss elimination method

   Multiplying (1) by (-0.0003120/0.5000) +  (2) we get

            

Or 

Substituting value of y in equation (1) we get

Hence

 

Q5) Solve the system of linear equations

                      

                    

                     

A5)

Using partial pivoting  by Gauss elimination method we rewrite the given equations as

                           (1)

                                 (2)

                           (3)

     Apply    and

                          (1)

                          (4)                       

                                      (5)

Apply )

                      (1)

                      (4)

                     

  Or     .

Putting value of z in we get .

Putting values of y and z in we get .

Hence the solution of the equation is .

 

Q6) Solve the equations-

A6)

Let
 

So that-

3.    

4.    

5.    

So

Thus-

Writing UX = V,

The system of given equations become-

By solving this-

We get-

Therefore the given system becomes-

Which means-

By back substitution, we get the values of x, y and z.

 

Q7) What is Jacobi’s Iteration method?

A7)

Let us consider the system of simultaneous linear equation

The coefficients of the diagonal elements are larger than the all other coefficients and are non zero. Rewrite the above equation we get

Take the initial approximation we get the values of the first approximation of .

 

Q8) Use Jacobi’s method to solve the system of equations:

 

A8)

Since

So, we express the unknown with large coefficient in terms of other coefficients.

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

 

Q9) Solve by Jacobi’s Method, the equations

 

A9)

Given equation can be rewrite in the form

                                         … (i)

                                        ..(ii)

                                         ..(iii)

Let the initial approximation be

 

Putting these values on the right of the equation (i), (ii) and (iii) and so we get

          

     

     

Putting these values on the right of the equation (i), (ii) and (iii) and so we get

 

     

     

Putting these values on the right of the equation (i), (ii) and (iii) and so we get

  0.90025

     

     

Putting these values on the right of the equation (i), (ii) and (iii) and so we get

 

     

     

Putting these values on the right of the equation (i), (ii) and (iii) and so we get

 

     

     

Hence   solution approximately 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) Use Gauss –Seidel Iteration method to solve the system of equations

   

A11)

Since

So, we express the unknown of larger coefficient in terms of the unknowns with smaller coefficients.

Rewrite the above system of equations

Let the initial approximation be

 

                        3.14814

                       

                                             

                                                                      2.43217

                       

                       

  

                        2.42571

                       

                                         

 

                        2.4260

                       

                       

Hence the solution correct to three decimal places is

 

 

Q12) Solve the following system of equations

    By Gauss-Seidel method.

A12)

Rewrite the given system of equations as

Let the initial approximation be

 

                       

                       

                                 

  

                       

                       

                       

  

                       

                       

                       

 

                       

                       

                       

Thus the required solution is

 

Q13) Solve the following equations by Gauss-Seidel Method

                     

                     

                        

                    

A13)

Rewrite the above system of equations

Let the initial approximation be

 

  

 

  

  

  

  

 

  

  

  

  

 

  

  

  

  

 

  

  

 

  

 

  

  

Hence the required solution is

 



Unit – 2


Solution of linear simultaneous Equations

Q1) Apply Gauss Elimination method to solve the equations:

    

A1)

Given                                                    Check Sum (sum of coefficient and constant)

                                     -1                            …. (I)

                                   -16                          …. (ii)

                                       5…. (iii)

(I)We eliminate x from (ii) and (iii)

Apply eq(ii)-eq(i) and eq(iii)-3eq(i) we get

                                             -1                            ….(i)

                                          -15                          ….(iv)

                                       8           ….(v)

(II) We eliminate  y from eq(v)

Apply

                                              -1                            ….(i)

                                          -15                          ….(iv)

                                   73           ….(vi)

(III) Back Substitution we get

                 From (vi) we get

                  From (iv) we get

                   From (i) we get 

Hence the solution of the given equation is

 

Q2) Solve the equation by Gauss Elimination Method:

   
A2)

Given

           

      

      

Rewrite the given equation as

                                   … (i)

                                              ….(ii)

                                               ….(iii)

                                        …(iv)

(I)                We eliminate x from (ii),(iii) and (iv) we get

Apply eq(ii) + 6eq(i), eq(iii) -3eq(i), eq(iv)-5eq(i) we  get

                                       …(i)

                                                     ….(v)

                                               ….(vi)

                                    …(vii)

(II)             We eliminate y   from (vi) and (vii) we get

Apply 3.8 eq(vi)-3.1eq(v) and 3.8eq(vii)+5.5eq(v) we get

                                         …(i)

                                ….(v)

                            …(viii)

                                 …(ix)

(III)           We eliminate z from eq (ix) we get

Apply 9.3eq (ix) + 8.3eq (viii), we get

                                       … (i)

                                ….(v)

                            …(viii)

        350.74u=350.74

       Or u = 1

(IV)          Back Substitution

From eq(viii)

Form eq(v), we get

From eq(i) ,

Hence the solution of the given equation is x=5, y=4, z=-7 and u=1.

 

Q3) Apply Gauss Elimination Method to solve the following system of equation:

     

A3)

Given                    … (i)

                            … (ii)

                            … (iii)

(I)                We eliminate x from (ii) and (iii)

Apply we get

                              … (i)

                            … (iv)

                           … (v)

(II)             We eliminate y from  (v)

Apply we get

                                                       … (i)

                            … (vi)

 

                                                 … (vii)

(III)           Back substitution 

From (vii)  

From (vi)

From (i)

Hence the solution of the equation is

 

Q4) Solve the system by Gauss Elimination method using partial pivoting

                                 

                                   

A4)

Given exact solution is

Given equations are

                                   

Using partial pivoting we rewrite the given equations as

                                      (1)

                                   (2)

Using Gauss elimination method

   Multiplying (1) by (-0.0003120/0.5000) +  (2) we get

            

Or 

Substituting value of y in equation (1) we get

Hence

 

Q5) Solve the system of linear equations

                      

                    

                     

A5)

Using partial pivoting  by Gauss elimination method we rewrite the given equations as

                           (1)

                                 (2)

                           (3)

     Apply    and

                          (1)

                          (4)                       

                                      (5)

Apply )

                      (1)

                      (4)

                     

  Or     .

Putting value of z in we get .

Putting values of y and z in we get .

Hence the solution of the equation is .

 

Q6) Solve the equations-

A6)

Let
 

So that-

3.    

4.    

5.    

So

Thus-

Writing UX = V,

The system of given equations become-

By solving this-

We get-

Therefore the given system becomes-

Which means-

By back substitution, we get the values of x, y and z.

 

Q7) What is Jacobi’s Iteration method?

A7)

Let us consider the system of simultaneous linear equation

The coefficients of the diagonal elements are larger than the all other coefficients and are non zero. Rewrite the above equation we get

Take the initial approximation we get the values of the first approximation of .

 

Q8) Use Jacobi’s method to solve the system of equations:

 

A8)

Since

So, we express the unknown with large coefficient in terms of other coefficients.

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

 

Q9) Solve by Jacobi’s Method, the equations

 

A9)

Given equation can be rewrite in the form

                                         … (i)

                                        ..(ii)

                                         ..(iii)

Let the initial approximation be

 

Putting these values on the right of the equation (i), (ii) and (iii) and so we get

          

     

     

Putting these values on the right of the equation (i), (ii) and (iii) and so we get

 

     

     

Putting these values on the right of the equation (i), (ii) and (iii) and so we get

  0.90025

     

     

Putting these values on the right of the equation (i), (ii) and (iii) and so we get

 

     

     

Putting these values on the right of the equation (i), (ii) and (iii) and so we get

 

     

     

Hence   solution approximately 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) Use Gauss –Seidel Iteration method to solve the system of equations

   

A11)

Since

So, we express the unknown of larger coefficient in terms of the unknowns with smaller coefficients.

Rewrite the above system of equations

Let the initial approximation be

 

                        3.14814

                       

                                             

                                                                      2.43217

                       

                       

  

                        2.42571

                       

                                         

 

                        2.4260

                       

                       

Hence the solution correct to three decimal places is

 

 

Q12) Solve the following system of equations

    By Gauss-Seidel method.

A12)

Rewrite the given system of equations as

Let the initial approximation be

 

                       

                       

                                 

  

                       

                       

                       

  

                       

                       

                       

 

                       

                       

                       

Thus the required solution is

 

Q13) Solve the following equations by Gauss-Seidel Method

                     

                     

                        

                    

A13)

Rewrite the above system of equations

Let the initial approximation be

 

  

 

  

  

  

  

 

  

  

  

  

 

  

  

  

  

 

  

  

 

  

 

  

  

Hence the required solution is

 



Unit – 2



Unit – 2



Unit – 2



Unit – 2



Unit – 2


Solution of linear simultaneous Equations

Q1) Apply Gauss Elimination method to solve the equations:

    

A1)

Given                                                    Check Sum (sum of coefficient and constant)

                                     -1                            …. (I)

                                   -16                          …. (ii)

                                       5…. (iii)

(I)We eliminate x from (ii) and (iii)

Apply eq(ii)-eq(i) and eq(iii)-3eq(i) we get

                                             -1                            ….(i)

                                          -15                          ….(iv)

                                       8           ….(v)

(II) We eliminate  y from eq(v)

Apply

                                              -1                            ….(i)

                                          -15                          ….(iv)

                                   73           ….(vi)

(III) Back Substitution we get

                 From (vi) we get

                  From (iv) we get

                   From (i) we get 

Hence the solution of the given equation is

 

Q2) Solve the equation by Gauss Elimination Method:

   
A2)

Given

           

      

      

Rewrite the given equation as

                                   … (i)

                                              ….(ii)

                                               ….(iii)

                                        …(iv)

(I)                We eliminate x from (ii),(iii) and (iv) we get

Apply eq(ii) + 6eq(i), eq(iii) -3eq(i), eq(iv)-5eq(i) we  get

                                       …(i)

                                                     ….(v)

                                               ….(vi)

                                    …(vii)

(II)             We eliminate y   from (vi) and (vii) we get

Apply 3.8 eq(vi)-3.1eq(v) and 3.8eq(vii)+5.5eq(v) we get

                                         …(i)

                                ….(v)

                            …(viii)

                                 …(ix)

(III)           We eliminate z from eq (ix) we get

Apply 9.3eq (ix) + 8.3eq (viii), we get

                                       … (i)

                                ….(v)

                            …(viii)

        350.74u=350.74

       Or u = 1

(IV)          Back Substitution

From eq(viii)

Form eq(v), we get

From eq(i) ,

Hence the solution of the given equation is x=5, y=4, z=-7 and u=1.

 

Q3) Apply Gauss Elimination Method to solve the following system of equation:

     

A3)

Given                    … (i)

                            … (ii)

                            … (iii)

(I)                We eliminate x from (ii) and (iii)

Apply we get

                              … (i)

                            … (iv)

                           … (v)

(II)             We eliminate y from  (v)

Apply we get

                                                       … (i)

                            … (vi)

 

                                                 … (vii)

(III)           Back substitution 

From (vii)  

From (vi)

From (i)

Hence the solution of the equation is

 

Q4) Solve the system by Gauss Elimination method using partial pivoting

                                 

                                   

A4)

Given exact solution is

Given equations are

                                   

Using partial pivoting we rewrite the given equations as

                                      (1)

                                   (2)

Using Gauss elimination method

   Multiplying (1) by (-0.0003120/0.5000) +  (2) we get

            

Or 

Substituting value of y in equation (1) we get

Hence

 

Q5) Solve the system of linear equations

                      

                    

                     

A5)

Using partial pivoting  by Gauss elimination method we rewrite the given equations as

                           (1)

                                 (2)

                           (3)

     Apply    and

                          (1)

                          (4)                       

                                      (5)

Apply )

                      (1)

                      (4)

                     

  Or     .

Putting value of z in we get .

Putting values of y and z in we get .

Hence the solution of the equation is .

 

Q6) Solve the equations-

A6)

Let
 

So that-

3.    

4.    

5.    

So

Thus-

Writing UX = V,

The system of given equations become-

By solving this-

We get-

Therefore the given system becomes-

Which means-

By back substitution, we get the values of x, y and z.

 

Q7) What is Jacobi’s Iteration method?

A7)

Let us consider the system of simultaneous linear equation

The coefficients of the diagonal elements are larger than the all other coefficients and are non zero. Rewrite the above equation we get

Take the initial approximation we get the values of the first approximation of .

 

Q8) Use Jacobi’s method to solve the system of equations:

 

A8)

Since

So, we express the unknown with large coefficient in terms of other coefficients.

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

 

Q9) Solve by Jacobi’s Method, the equations

 

A9)

Given equation can be rewrite in the form

                                         … (i)

                                        ..(ii)

                                         ..(iii)

Let the initial approximation be

 

Putting these values on the right of the equation (i), (ii) and (iii) and so we get

          

     

     

Putting these values on the right of the equation (i), (ii) and (iii) and so we get

 

     

     

Putting these values on the right of the equation (i), (ii) and (iii) and so we get

  0.90025

     

     

Putting these values on the right of the equation (i), (ii) and (iii) and so we get

 

     

     

Putting these values on the right of the equation (i), (ii) and (iii) and so we get

 

     

     

Hence   solution approximately 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) Use Gauss –Seidel Iteration method to solve the system of equations

   

A11)

Since

So, we express the unknown of larger coefficient in terms of the unknowns with smaller coefficients.

Rewrite the above system of equations

Let the initial approximation be

 

                        3.14814

                       

                                             

                                                                      2.43217

                       

                       

  

                        2.42571

                       

                                         

 

                        2.4260

                       

                       

Hence the solution correct to three decimal places is

 

 

Q12) Solve the following system of equations

    By Gauss-Seidel method.

A12)

Rewrite the given system of equations as

Let the initial approximation be

 

                       

                       

                                 

  

                       

                       

                       

  

                       

                       

                       

 

                       

                       

                       

Thus the required solution is

 

Q13) Solve the following equations by Gauss-Seidel Method

                     

                     

                        

                    

A13)

Rewrite the above system of equations

Let the initial approximation be

 

  

 

  

  

  

  

 

  

  

  

  

 

  

  

  

  

 

  

  

 

  

 

  

  

Hence the required solution is