How do I plot a point at the x intercept on this graph?

e=1;
sigma=0.154;
r=linspace(0.154,1,100);
U = @(e,sigma,r) 4*e*((sigma./r).^12)-((sigma./r).^6);
norm_r = r./sigma;
figure
plot(norm_r,U(e,sigma,r))
title('Lennard-Jones Potential')
xlabel('Distance (nm)')
ylabel('Potential Energy')

[dpb]

Not sure precisely what you want to add where???

[Rhianne Tallarico]

This code plots a curved line, I am looking to find the x intercept value of the line, and plot a marker at that point. Thanks!

Answer 1

[Are Mjaavatten]

Let U be a function of r only and find the solution to U(r) = 0:

e=1;
sigma=0.154;
r=linspace(0.154,1,100);
U = @(r) 4*e*((sigma./r).^12)-((sigma./r).^6);
norm_r = r./sigma;
figure
plot(norm_r,U(r))
title('Lennard-Jones Potential')
xlabel('Distance (nm)')
ylabel('Potential Energy')
norm_r_0 = fzero(U,1)/sigma;
hold on; plot(norm_r_0,0,'*r')