. solve the ode system below using • ode numerical solver • the symbolic toolbox • compare and visualize the solutions from both methods in a plot. dx dt = z + 4, x(0) = 2 dz dt = −3x, z(0) = 3 in matlab

To solve the given system of first-order ordinary differential equations using both the symbolic and numerical methods in MATLAB, you can follow these steps:

  1. Using the Symbolic Toolbox:

    • Define the symbolic variables and the system of equations:

      main.m
      syms x(t) z(t)
      eq1 = diff(x) == z + 4;
      eq2 = diff(z) == -3*x;
      
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    • Define the initial conditions:

      main.m
      cond = [x(0) == 2, z(0) == 3];
      
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    • Solve the system symbolically:

      main.m
      sol_sym = dsolve([eq1, eq2], cond);
      
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  2. Using the numerical solver:

    • Define a function that represents the system of equations:

      main.m
      function dxdt = ode_func(t, x)
          dxdt = [x(2) + 4; -3*x(1)];
      end
      
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    • Define the initial conditions:

      main.m
      x0 = [2; 3];
      
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    • Solve the system numerically using ode45:

      main.m
      tspan = [0 10];
      [t, sol_num] = ode45(@ode_func, tspan, x0);
      
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  3. Compare and visualize the solutions:

    • Extract the symbolic solutions:

      main.m
      x_sym(t) = sol_sym.x;
      z_sym(t) = sol_sym.z;
      
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    • Plot the solutions:

      main.m
      figure;
      plot(t, sol_num(:, 1), 'b-', 'LineWidth', 2);  % Numerical solution for x
      hold on;
      fplot(x_sym, tspan, 'r--', 'LineWidth', 2);  % Symbolic solution for x
      plot(t, sol_num(:, 2), 'g-', 'LineWidth', 2);  % Numerical solution for z
      fplot(z_sym, tspan, 'm--', 'LineWidth', 2);  % Symbolic solution for z
      hold off;
      legend('Numerical solution for x', 'Symbolic solution for x', 'Numerical solution for z', 'Symbolic solution for z');
      xlabel('t');
      ylabel('Solution');
      title('Comparison of Numerical and Symbolic Solutions');
      
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This will solve the given system of ODEs using both the symbolic and numerical methods, and then plot and compare the solutions.

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