Plot the line and give maximum value of y and x at which y is maximum?

In this I want to put a line passes through maximum value of y and x axis for both plots, want to know the value of x at y=0 and ymax in legend or somewhere in figure?

[Azzi Abdelmalek]

In your plot, y is never equal to zero

[RS]

I want to put line from maximum value of y

Answer 1

[Azzi Abdelmalek]

Edit

Example

close
x=0:0.1:10;
y1=sin(x)./(x+1);
y2=sin(x-1)./(x+1);
plot(x,y1);
hold on
plot(x,y2,'r')
a=get(gca,'xlim')
[b1,idx1]=max(y1);
[b2,idx2]=max(y2);
i1=find(abs(y1)<0.01,1);
i2=find(abs(y2)<0.01,1);
plot(a,[b1 b1]);
plot(a,[b2 b2],'r');
leg1=sprintf('x=%.2f, y=ymax1=%.2f',x(idx1),b1)
leg2=sprintf('x=%.2f, y=ymax2=%.2f',x(idx2),b2)
legend({leg1,leg2})
hold off