Newton-raphson for a specific function

I would like to use Newton raphson to solve the following equation:

(([L]_0*(1-injectvol/V)^n )-([M]_0*(1-(1-injectvol/V)^n ))*x )*(N-l*x )^l-k*x*(N-(l-1) x )^(l-1)=0.

where [L]_0, [M]_0, injectvol and V are known constants, n is a known variable and assuming values of N, k and l which are also constants.

With the following script:

dx=1;    % Change in variable is set to a high value  
x=input('Enter the initial estimate -> ');   % Initial estimate
iter = 0; % Iteration counter  
disp('iter   Dc        J         dx         x') % Heading for result
while abs(dx) >= 0.000001 && iter < 100 % Test for convergence  
    iter = iter + 1; % No. of iterations   
    Dc=(((L*(1-0.000006/0.000950)^(n))-(M*(1-(1-0.000006/0.000950)^(n)))*x)*(N-l*x)^(l)-k*x*(N-(l-1)*x)^(l-1)); % Residual
    J = diff(Dc,x); % Derivative
    dx= Dc/(J); %Change in variable
    x=x+dx; % Successive solution  
    fprintf('%g', iter), disp([Dc, J, dx, x])
end

I keep getting an error:

Error in newtontest (line 9)
dx= Dc/(J);  %Change in variable

can anyone help me with what is wrong?

best regards: Emil Stender

Answer 1

[Jae Song]

In the following line:

dx= Dc/(J);

if the computation of Dc/(J) is not matrix computation, you need to use ./

Dc./(J)

Answer 2

[Emil G. P. Stender]

Many thanks that worked