I am getting the following error when I run my script: Invalid expression. When calling a function or indexing a variable, use parentheses. Otherwise, check for mismatc

I'm running the following script in Matlab and getting the following error message:

h = h + (1/6) (k1 + 2k2 + 2*k3 + k4);

↑

Invalid expression. When calling a function or indexing a variable, use parentheses.

Otherwise, check for mismatched delimiters.

Could you please assist me with clearing the error.

% Given data
h0 = 4.84;    % Initial height (m)
t0 = 0;       % Initial time (hrs)
tf = 15;      % Final time (hrs)
h_target = 3.5;  % Target height (m) after 3.5 hrs
% Function representing the differential equation
dhdt = @(t, h, k) k * sqrt(h);
% Runge-Kutta method
h = h0;
t = t0;
k = 0; % To be determined
tolerance = 1e-6;
while t < 3.5
    k1 = dhdt(t, h, k);
    k2 = dhdt(t + 0.5, h + 0.5 * k1, k);
    k3 = dhdt(t + 0.5, h + 0.5 * k2, k);
    k4 = dhdt(t + 1, h + k3, k);
    h = h + (1/6) * (k1 + 2*k2 + 2*k3 + k4);
    t = t + 1;
    k = (h_target - h) / (tf - t); % Adjusting k based on target height
end
% After 3.5 hours
fprintf('Height after 3.5 hours: %.4f m\n', h);

Height after 3.5 hours: 4.2815 m

% Continue solving until tf
while t < tf
    k1 = dhdt(t, h, k);
    k2 = dhdt(t + 0.5, h + 0.5 * k1, k);
    k3 = dhdt(t + 0.5, h + 0.5 * k2, k);
    k4 = dhdt(t + 1, h + k3, k);
    h = h + (1/6) * (k1 + 2*k2 + 2*k3 + k4);
    t = t + 1;
end
% Display the final height
fprintf('Height after %.1f hours: %.4f m\n', tf, h);

Height after 15.0 hours: 2.8171 m

Answer 1

[VBBV]

 h = h + (1/6) * (k1 + 2*k2 + 2*k3 + k4);
             % <> multplication operator is missing here 

[VBBV]

implicit multipiication is not allowed in Matlab expressions