把下面的程序放到一个m文件里,直接运行
function [T,Y] = stest
tspan = [0,5];
Dy0 = 0;
y0 = 30*pi/180;
[T,Y] = ode45(@f,tspan,[y0,Dy0]);
plot(T,Y);
xlabel('t/s');
ylabel('y,dy')
legend('y','dy')
function dy = f(t,y)
dy = zeros(2,1);
dy(1) = y(2);
dy(2) = -3*sin(y(1));
给出的微分方程的初值条件为多少?