How to add markers to a plot after using fzero

I am working on making a plot of y vs y'. I have constructed the plot and used the fzero function initialized at -4, -2, 0, 2, 4 to find all zeros of y'. I am trying to add these zeros to the plot already made as markers. Thanks for your help!

x=-2*pi : 2*pi;
y=3*x.*sin(x)-2*x; 
y1=3*sin(x)+3*x.*cos(x)-2;
plot(x,y,'-',x,y1, '--')  
xlabel('\bf\itx-axis\rm')  
ylabel('\bf\ity-axis\rm')   
legend('y=3xsin(x)-2x','y1=3sin(x)+3xcos(x)-2', 'Location', 'S')
x0 =-4; x1=-2; x2=0; x3=2; x4=4; 
z0 = fzero('3*sin(x)+3*x.*cos(x)-2', x0)
z1 = fzero('3*sin(x)+3*x.*cos(x)-2', x1)
z2 = fzero('3*sin(x)+3*x.*cos(x)-2', x2)
z3 = fzero('3*sin(x)+3*x.*cos(x)-2', x3)
z4 = fzero('3*sin(x)+3*x.*cos(x)-2', x4)

Answer 1

[Star Strider]

I would use a loop to create a vector for ‘z’:

x=-2*pi : 2*pi;
y=3*x.*sin(x)-2*x; 
y1=3*sin(x)+3*x.*cos(x)-2;
x0 = [-4, -2, 0, 2, 4];
for k1 = 1:numel(x0)
    z(k1) = fzero('3*sin(x)+3*x.*cos(x)-2', x0(k1));
end

figure
plot(x,y,'-',x,y1, '--') 
hold on
plot(z, zeros(size(z)), 'pg')                                                   
hold off
xlabel('\bf\itx-axis\rm')  
ylabel('\bf\ity-axis\rm')   
legend('y=3xsin(x)-2x','y1=3sin(x)+3xcos(x)-2', 'Location', 'S')