Unable to get a plot in a Graph

I need to plot a graph based as shown in the attached image. I have written the coding for the equation which is in attached image;

%First way: I defined it as a function and I got a graph but with no plot at all.

f = @(Le, P) pi*a*d*Le+sqrt((pi^2*G*E*d^3)/2);
ezplot(f, [0.0 Le])

%Second way: It would be helpful if you could also tell me how to plot if I write the equation coding by the following way;

P=pi*a*d*Le+sqrt(pi^2*Gd*Ef*df^3/2);

%The reason I write like the second way is because I am writing set of equations as a function, later I will solve this function to get a simulation.

Please note that the values of the other variables were already defined in the function as the following;

a=3.0, d=14, Le=0.46, G=6.0, E=60

I am getting a graph with no plot. I only need to get that line graph (as shown in the image) marked as "prediction", not the scattered (experiment) plot.

Can someone help me correct it please?

Answer 1

[Stephen23]

Method One: ezplot:

>> a=3.0; d=14; G=6.0; E=60;
>> f = @(Le) pi*a*d*Le+sqrt((pi^2*G*E*d^3)/2);
>> ezplot(f, [0.0,1.2])

Method Two: plot:

>> Le = 0:0.01:1.2;
>> P = pi*a*d*Le+sqrt(pi^2*G*E*d^3/2);
>> plot(Le,P)

[jack carter]

Thank you for your detailed answer, it has solved the problem