Im trying to plot stable and unstable equilibrium solutions for my graph but Im not sure where or how to use the fzero function to do so for dx1 and dx2

close all; clear all;

% This Matlab code generates a vector field for the system of ODEs

% dx1/dt = f(x1,x2), dx2/dt = g(x1,x2)

x1min = -1; x1max = 6; x2min = -1; x2max = 6;

x1step = 0.5; x2step = 0.5;

[x1, x2] = meshgrid(x1min:x1step:x1max, x2min:x2step:x2max);

a = 1.5;

b = 1.1;

g =2.5;

d =1.4;

dx1 = -a.*x1+b.*x1.*x2;

dx2 = g.*x2-d.*x1.*x2;

dx1 = dx1./sqrt(dx1.^2 + dx2.^2);

dx2 = dx2./sqrt(dx1.^2 + dx2.^2);

axis([x1min x1max x2min x2max]);

xlabel('$x1$','Interpreter','latex')

ylabel('$x2$','Interpreter','latex')

title('Vector field example','Interpreter','latex')

nullX1= -a + b.*x2;

nullX2= g - d.*x1;

x=linspace(-1,6,size(nullX1,1));

quiver(x1, x2, dx1,dx2,'AutoScaleFactor',0.5)

hold on

plot(x,nullX1,'r-')

hold on

plot(x,nullX2,'k-')

hold on

legend('flow','nullX1','nullX2')

[t,x] = ode45(@ODE45Fun,[0,30],[0.5,1]);

plot(t,x(:,1),'g-',t,x(:,2),'b-')

hold on

fzero(dx1,0)

grid

xlabel('Number of Years')

ylabel('Predator-Prey Pop.')

title('Lotka Voltera Pred-Prey Pop.Figure1')