I'm trying to get this plot to show me a function I can code in desmos, but is giving me the wrong plot in matlab. Any help would be appreciated

clc, close all, clear vars
% Pieces of the function
Q = 9.4*10^-6; % C
q = 2.4*10^-5; % C
e = 8.854*10^-12; % C^2/(Nm^2): permittivity constant
F = 0.3; %  Force, newtons
R = 0.1; % radius, m
z = -0.1:0.01:0.5;
force = @(z) Q*q.*z/(2*e)*(1-z/sqrt(z.^2 + R^2))-F;
plot(z, force(z), 'g', 'LineWidth', 2);
hold on
yline(0, 'r', 'LineWidth', 2);
grid on
xlabel('Distance (m)','FontSize',14);
ylabel('Force', 'FontSize',14);
title('Force vs Distance, problem 1a')
lgd = legend({'Force/Distance', 'Force at 0.3 N'},'Fontsize', 14, 'LineWidth', 1.1);

Answer 1

[Walter Roberson]

clc, close all, clear vars
% Pieces of the function
Q = 9.4*10^-6; % C
q = 2.4*10^-5; % C
e = 8.854*10^-12; % C^2/(Nm^2): permittivity constant
F = 0.3; %  Force, newtons
R = 0.1; % radius, m
z = -0.1:0.01:0.5;
force = @(z) Q*q.*z/(2*e).*(1-z./sqrt(z.^2 + R^2))-F;
plot(z, force(z), 'g', 'LineWidth', 2);
hold on
yline(0, 'r', 'LineWidth', 2);
grid on
xlabel('Distance (m)','FontSize',14);
ylabel('Force', 'FontSize',14);
title('Force vs Distance, problem 1a')
lgd = legend({'Force/Distance', 'Force at 0.3 N'},'Fontsize', 14, 'LineWidth', 1.1);

[Christopher]

Perfect! I don't know what I was doing wrong but it works now, thanks!

[Voss]

You had a * where you needed a .* and a / where you needed a ./

https://www.mathworks.com/help/matlab/matlab_prog/array-vs-matrix-operations.html