is this definition of the natural log VALID?

What is e and ln(x)? (Euler's Number and The Natural Logarithm)

a neat parameterized integral identity

The Simplest Math Problem No One Can Solve - Collatz Conjecture

a physicist's favorite "FUNCTION"

The History of the Natural Logarithm - How was it discovered?

just an average recursion...OR IS IT?

Deriving Euler's formula four ways!

What Lies Between a Function and Its Derivative? | Fractional Calculus

a quaternion version of Euler's formula

Algebra Basics: What Is Algebra? - Math Antics

Why don't they teach simple visual logarithms (and hyperbolic trig)?

The Riemann Hypothesis, Explained

What is the i really doing in Schrödinger's equation?

The SAT Question Everyone Got Wrong

Factor ANY Quadratic Equation Without Guessing | Outlier.org

Why π is in the normal distribution (beyond integral tricks)

WHY are we finding pi HERE?

The Oldest Unsolved Problem in Math

The Most Controversial Number in Math

DIFFERENTIATING a CONTINUED FRACTION?!