solution with the Runge-Kutta method HELPP

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Bilal Ates 2020-6-25

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回答： James Tursa 2020-6-25

for i=1:(length(x)-1) % calculation loop

k_1 = F_xy(x(i),y(i));

k_2 = F_xy(x(i)+0.5*h,y(i)+0.5*h*k_1);

k_3 = F_xy((x(i)+0.5*h),(y(i)+0.5*h*k_2));

k_4 = F_xy((x(i)+h),(y(i)+k_3*h));

y(i+1) = y(i) + (1/6)*(k_1+2*k_2+2*k_3+k_4)*h; % main equation

end

Employ the Classical RK-4 method to integrate the given equations from x=0 to x=1 using at least one single step with the initial conditions, y(0)=2 and z(0)=4.

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Steven Lord 2020-6-25

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Answer 1

James Tursa 2020-6-25

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This is clearly a homework/exam question, so I will only offer hints. The code you have posted is for a single scalar differential equation. But you have two of these equations. You can either duplicate the stuff inside the loop for the z equation, or you can turn the code into a vector form that can handle any number of equations. I prefer the second approach because it is less code to write, and once you have written it, it will work for any number of equations. But either approach can work.