Attempted to access x(4); index out of bounds because numel(x)=2

I understand my x vector is made of 2 numerals but how can I expand my matrix without changing the initial conditions vector?

% Set Variables
global m l cd g theta0 ft
m = 2.5; %[kg]
l = 12; %[m]
cd = 0.11; %[N-s/m]
g = 9.81; %[m/s^2]
theta0 = 45; % [rad]

[t,x] = ode45(@rocketEOM, [0 45], [0 0]); %computes 2 ODEs 
ft = getThrust(t); %function calls thrust for a given time

here is my function file:

function xd = rocketEOM(t,x)
global m l cd g theta0 ft
% x(2) = x velocity
% x(4) = y velocity
xd = (ft/m) - (cd*hypot(x(2),x(4))/m) - g*sin(theta0);
end

[David Sanchez]

I think you are not defining your problem properly. In your function rocketEOM, you make use of x(2) and x(4). Why do not you call them x(1) and x(2) and solve the issue with the error?

Besides, rocketEOM uses ft before it is defined by getThrust.