fsolve with a changing variable using a for loop

I know this is wrong, but I don't have any idea how to do it. Trying to solve for x at each of the different points of u. I want to output an array of answers that correspond.

u is a 10143x1 array.

for i = 1:10143
    fun(i) = @(x) -(h^2-2*h*x+x^2)*(0.04)-(1025*u(i)^2*x)/g;
    y(i) = fsolve(fun,-75);
end

Answer 1

[Walter Roberson]

syms h x U g
sol = solve(-(h^2-2*h*x+x^2)*(0.04)-(1025*U^2*x)/g,x);
y = subs(sol, U, u(:).');

As you are looking for negative values, your desired solution will be y(1,:) if g is positive,and y(2,:) if g is negative.

Note: the solutions are complex outside of u in the interval +/- 2/1025 * sqrt(41) * sqrt(g*h)