B =
Some equations cannot be solved analytically because they are too complicated or because there are no functions available that can be used to express the solution. Yours seems to be one of them.
E.g. this simple-looking equation already fails to be solved:
syms a x
eqn = exp(x) - a*cos(x) == 0
solve(eqn,x)
You will need to give values to the parameters and solve the equation numerically using "fzero" or "fsolve".