matlab数学实验，常微分方程

clear; close;

figure

[t,y]=ode45(@why13,[0,10],[15,0]);

subplot(2,1,1)

plot(t,y(:,1))

xlabel('t') 

ylabel('y1')

[v,y]=ode45(@why17,[0,10],[10,0]);

subplot(2,1,2)

plot(v,y(:,1))

xlabel('v') 

ylabel('y1')

function f=why13(t,y)

f=[y(2), -9.8*sin(y(1))]';

end

function f=why17(v,y)

f=[y(1), v]';

end