Natural Log of 0.9

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What is ln 0.9?

Answer

ln 0.9 ≈
−0.1054

ln is the natural log, base e ≈ 2.71828.

≈ — the logarithm is irrational; the value is rounded to 4 decimal places.

ln 0.9 is the power you raise e ≈ 2.71828 to, to get 0.9: ey = 0.9.

e⁻¹ ≈ 0.3679 < 0.9 < e⁰ = 1, so −1 < ln 0.9 < 0

Oxy1

Answer point ≈ (0.9, −0.1054).

The curve y = ln x passes through (1, 0) and (e, 1) and rises: for x > 1 the log is positive, for 0 < x < 1 negative.

Log of 0.9 in different bases
BaseNotationValue
eln 0.9≈ −0.1054
10log 0.9≈ −0.0458
2log₂ 0.9≈ −0.1520

See Also

FAQ

What is ln 0.9?

ln 0.9 ≈ −0.1054

What is the difference between ln 0.9 and log 0.9?

ln 0.9 is the logarithm to base e, log 0.9 is to base 10: ln 0.9 ≈ −0.1054, log 0.9 ≈ −0.0458. One is the other divided by ln 10: log 0.9 = ln 0.9 / ln 10 ≈ −0.0458.

What does log without a base mean?

At school and on a calculator, log x without a base is the common log, base 10: log 100 = 2. In Python, math.log(x) is the natural log ln x; in Excel, LN is the natural log and LOG is base 10.