Logarithm base a

The logarithm with base $a$, $\log_a$, is defined by $$\log_a(z)=\dfrac{\log(z)}{\log(a)},$$ where $\log$ denotes the logarithm.

Properties

Log base a in terms of logarithm base b
Log a(z)=1/log b(a)
Log e(z)=log(z)
Log 10(z)=log(z)/log(10)
Log 10(z)=log 10(e)log(z)
Log(z)=log(10)log 10(z)

See also

Logarithm
Logarithm (multivalued)

References

• 1964: Milton Abramowitz and Irene A. Stegun: Handbook of mathematical functions ... (previous) ... (next): $4.1.18$