"Index exceeds the number of array elements. Index must not exceed 1."

Beginner coder here. I'm trying to run my code and I've got an index error. I don't know how to fix it. I have a bunch of variables assigned to number values, so I left those out, but I know my error is stemming from this loop. Again, I don't know how to fix it.

Any help would be greatly appreiciated

for i=2:nx
    error=1;
    x=x+delta_x;
    delta2_old = delta2(i-1); 
    while error > epsilon
        alpha = (3/10) - (lambda/120);
        beta = (37/315) - (lambda/945) - ((lambda^2)/9072);
        gamma = 2 + (lambda/6);
        u0 = (h1*U) / (h1 - ((x*(h1-h2))/L) - ((alpha*delta2_old)/beta));
        delta2_new = sqrt( ((d2^2) + (2*v*(beta*gamma)/u0)*delta_x) / (1 + (2*(2 + (alpha/beta))) * ((u0 - u_0)/u0))   );
        error = abs((delta2_new - delta2_old)/delta2_new);
        u0_old = u0_new;
        delta2_old = delta2_new;
    end
    delta2(i)= delta2_new;
    delta1(i)= (alpha*delta2(i))/beta;
    tau(i)= beta*gamma*((mu*u0(i))/delta2(i));
    xv(i)=x;
    iv(i)=i;
end

Answer 1

[Torsten]

tau(i)= beta*gamma*((mu*u0)/delta2(i));

instead of

tau(i)= beta*gamma*((mu*u0(i))/delta2(i));

[Victoria Rodriguez]

Thanks!