beta_0 = -4.898
beta_1 = 3.964

p = exp(beta_0)/(1 + exp(beta_0))
print(p)

LD50 = -beta_0/beta_1
print(LD50)

p = 0.001
lhs = log(p/(1-p))
print(lhs)
print((lhs - beta_0)/beta_1)