Log Notation

• log ₐ b ʳ (a = base, b = argument, r = exponent)

• 10 is assumed when no base is written log b ʳ = log ₁₀ b ʳ

Natural Log Notation

• ln ₑ x (e is the base)

Logarithm Properties

• log ₐ b ᶜ = c log ₐ b and log ₐ b ⁻¹ = - log ₐ b

• log ₐ a ʳ = r

• log ₐ (b * c) = log ₐ b + log ₐ c

• log ₐ (b / c) = log ₐ b - log ₐ c

Values of a log expression

• log 0 and log (-1) = undefined (logs of zeros and negative numbers are undefined)

• log 1 = 0