function u=svexmp1(T,XX,TT)
%wave equation with zero DC BC in (0,pi)
%initial position - sin(x)+4*sin(5*x)
%initial momentum - 0
x=linspace(0,pi,XX);
t=linspace(0,T,TT);
u=zeros(TT,XX);
for i=1:TT
    u(i,:)=cos(2*t(i))*sin(x)+4*cos(10*t(i))*sin(5*x);
end

figure(1)
subplot(6,1,1)
plot(x,u(1,:))
subplot(6,1,2)
plot(x,u(TT/5,:))
subplot(6,1,3)
plot(x,u(2*TT/5,:))
subplot(6,1,4)
plot(x,u(3*TT/5,:))
subplot(6,1,5)
plot(x,u(4*TT/5,:))
subplot(6,1,6)
plot(x,u(TT,:))




