How to solve a third order polynomial

I have the correct code to solving this question, but I was wondering why in line 2 there were the numbers 1,2,4,5? I do not understand why those specific numbers are there.

% Output a third-order polynomial function with the coefficients as the
% input variables

x = 0:10;
output = polynomial(x,1,2,4,5);  % HELP HERE 

% Convert the function to a function handle
poly_handle = @polynomial;
output2 = poly_handle(x,1,2,4,5);

[Star Strider]

I cannot find a built-in function called ‘polynomial’ in the online documentation.

Are you asking about writing the function, or help on using it?