Question

I need to use ode45 or ode23 in matlab to plot the change of y1,y2 and y3 with time

y0=2.8

and the following first order differential equations :

dy1/dt=(y0-1.625y1)/6.25

dy2/dt=(y1-1.625y2)/6.25

dy3/dt=(y2-1.625y3)/6.25

Answer 1

Code:

clc
clear

tspan = [0 10];
y0 = 2.8;
y02 = 0;
y03 = 0;

[t,y1] = ode45(@(t,y1) (y0-1.625*y1)/6.25, tspan, y0);
plot(t,y1,'-ro');
hold on
[t,y2] = ode45(@(t,y2) (y1(end)-1.625.*y2)./6.25, tspan, y02);
plot(t,y2,'-ks');
[t,y3] = ode45(@(t,y3) (y2(end)-1.625*y3)/6.25, tspan, y03);
plot(t,y3,'-b^');
legend('y1', 'y2', 'y3');
hold off

Output: