I'm trying to solve the below equation to get the value of b
from sympy import symbols, solve
import numpy as np
b = symbols('b')
expr = (30*np.log(b)/2.549*0.665*(1.5-math.exp(-0.4*(b-1))))-50
sol = solve(expr)
print(sol)
but the error shows 'loop of ufunc does not support argument 0 of type Symbol which has no callable log method' in line 4