That’s a bit long to copy and paste, so I won’t.
The Symbolic Math Toolbox doesn’t ‘know’ what the real and imaginary parts of your function are because you only told it that:
syms e1 e2 positive
meaning that the real parts of those variables are positive, but that they could be complex. I would use the syms declaration to be:
syms e1 e2 real
to remove that ambiguity, if you want to define those symbolic variables to be real.
With respect to simplifying it, I would use:
x = simplify(x, 'steps',20)
x = vpa(x, 8)
You can of course combine them into one assignment, but keeping them as two statements will let you see the results of each operation.
