Python Logarithm Function

logarithm, numpy, python, sympy

Solution

I may be misunderstanding what you need to do because you said you tried sympy already. However, it looks like you just want to solve for x in an algebraic equation.

Solving for x in the equation

log(x+1)+log(4-x)=log(100)

using sympy would be

>>> from sympy import Symbol, solve, log
>>> x = Symbol('x')
>>> solve(log(x+1) + log(4-x) - log(100), x)
[3/2 - 5*sqrt(15)*I/2, 3/2 + 5*sqrt(15)*I/2]

If you want, you can check that these two solutions are correct with numpy.

>>> import numpy as np
>>> a = 3/2 - 5*np.sqrt(15)*1j/2
>>> b = 3/2 + 5*np.sqrt(15)*1j/2
>>> np.log(a + 1) + np.log(4-a)
(4.6051701859880918+0j)
>>> np.log(b + 1) + np.log(4-b)
(4.6051701859880918+0j)
>>> np.log(100)
4.6051701859880918

Is that not what you are looking for?

Problem

I'm looking for an example of operations with logarithms in Python. I've tried with `sympy` and `numpy` and I still can't do what I want. For example, for an input like this: ``` log(x+1)+log(4-x)=log(100) # it's just an example ``` the output should give me the `x` value. I need to do this with any other functions like `log(x+1)=4` or `log(x)-log(x+1)=log(x)`. Is there some method or somewhere (documentation or similar) where can I find how to do this?

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