You got a "numerical" result. But because the result is symbolic, that is the symbolic result. pi, and square roots are as you would expect in such a result. Then you tried to simplify them, but they were already in a maximally simple form as a symbolic result. It was not simplification you weree looking for, but to express them as floating point numbers.
You can turn them into actual floating point numbers using double. Or you can use vpa, to turn them into floaing point numbers, but as a symbolic form of a floating point number.
For example, you got this result:
X = str2sym('(3*pi*39270^(1/2))/1666')
X =
As far as the symbolic toolbox is concerned, the job is done. That was fun, right? But you wanted real numbers. DOUBLE or VPA will do the job.
vpa(X)
ans = 1.1210541248532242623574383591283
So double turns it into a double precision number, VPA turns it into a floating point number, but still in symbolic form. Here with 32 significant digits as the default for VPA, so roughly twice what a double gives you. (Remember that a double only displayed 5 digits there, but the number is stored as full double precision.)
