The fzero function will only return one value for each initial estimate. You need to provide different initial estimates in different calls to it, if you want other roots. (For several roots, this usually requires a for loop.) Plotting the results is then straightforward.
Try this:
f=@(x)x.^2-5*sin(x);
p1 = fzero(f,1);
p2 = fzero(f,5);
fplot(f,[-1,3])
hold on
plot([p1,p2], [0 0], 'p')
hold off
