Why does the solve function give me matrix instead of a number ?

Im using the solve command and it gives me 3x1 matrix instead of a number so I get error because its not the same size on the left and right. Im using this

syms h;
g= subs(f, [x1,x2], [X1(i)+s(1)*h, X2(i)+h*s(2)]);
dg_dh=diff(g,h);
h = solve(dg_dh,h);
    

and g and dg_dh are both just numbers but my h is 3x1 matrix but I need it to be a number, can anyone see what Im doing wrong here?

This is what I get for h

root(z^3 - (35175*z^2)/60236 + (22211250*z)/226773481 - 10890625/1814187848, z, 1)
 root(z^3 - (35175*z^2)/60236 + (22211250*z)/226773481 - 10890625/1814187848, z, 2)
 root(z^3 - (35175*z^2)/60236 + (22211250*z)/226773481 - 10890625/1814187848, z, 3)
 

[Torsten]

Maybe dg_dh has three roots instead of only one ?

Answer 1

[John D'Errico]

You get 3 values, because there were 3 solutions found.

You can convert them to numbers using vpa.

syms z
vpa([root(z^3 - (35175*z^2)/60236 + (22211250*z)/226773481 - 10890625/1814187848, z, 1)
 root(z^3 - (35175*z^2)/60236 + (22211250*z)/226773481 - 10890625/1814187848, z, 2)
 root(z^3 - (35175*z^2)/60236 + (22211250*z)/226773481 - 10890625/1814187848, z, 3)],15)

ans =
 0.113779972551139 - 0.0624336484642866i
 0.113779972551139 + 0.0624336484642866i
                       0.356393172634623

So we see two complex roots and one real root.

You asked for a solution, but solve cannot know which solution you might wish to see.