I have used two different methods for same problem and getting different plots

    %----------------CODE - 1-----------------------------  
    function second_order_ode
      clc
      clear
      t = 0:0.001:3; % time scale
      initial_x = 0;
      initial_dxdt = 0;

      [t,x] = ode45 ( @rhs, t, [initial_x, initial_dxdt]);
      plot(t,x(:,2));
      xlabel('t'); ylabel('x');
      title('Solution to ODE d^2x/dt^2+5dx/dt-4x(t)=sin(10t)')
      disp([t,x(:,2)])

       function dxdt=rhs(t,x)
              dxdt_1 = x(2);
              dxdt_2 = -5*x(2)+4*x(1)+sin(10*t);
      dxdt = [dxdt_1; dxdt_2];
      end
      end
    %----------------CODE - 2----------------------------- 
  clc
  clear
  syms x t
  x = Dsolve('D2x + 5*Dx - 4*x = sin(10*t)','x(0)=0','Dx(0)=0','t')
  tt = 0:.01:3
  xx = subs(x,t,tt)
  plot(tt,xx)

[MathReallyWorks]

Your code is not running properly. Please edit it.

Attach your output as well to get the proper answer.

[Taha Abbas Bin Rashid]

%----------------CODE - 1-----------------------------  
    function second_order_ode
      clc
      clear
      t = 0:0.001:3; % time scale
      initial_x = 0;
      initial_dxdt = 0;
      [t,x] = ode45 ( @rhs, t, [initial_x, initial_dxdt]);
      plot(t,x(:,2));
      xlabel('t'); ylabel('x');
      title('Solution to ODE d^2x/dt^2+5dx/dt-4x(t)=sin(10t)')
      disp([t,x(:,2)])
       function dxdt=rhs(t,x)
              dxdt_1 = x(2);
              dxdt_2 = -5*x(2)+4*x(1)+sin(10*t);
      dxdt = [dxdt_1; dxdt_2];
      end
      end

    if true
      % code
    end

[Taha Abbas Bin Rashid]

    %----------------CODE - 2----------------------------- 
    clc
    clear
    syms x t
    x = Dsolve('D2x + 5*Dx - 4*x = sin(10*t)','x(0)=0','Dx(0)=0','t')
    tt = 0:.01:3
    xx = subs(x,t,tt)
    plot(tt,xx)

[Taha Abbas Bin Rashid]

Try running both codes separately

[Taha Abbas Bin Rashid]

Output of Code 1

[Taha Abbas Bin Rashid]

Output of code 2

Answer 1

[Walter Roberson]

After you find the numeric solution, you plot the second output, which is the derivative.

After you find the symbolic solution, you plot the function itself.

[Taha Abbas Bin Rashid]

Thank you Sir Thank you so much