DefinitionThe
logarithm of a number
x with respect to base
b is the exponent to which
b has
to be raised to yield
x. In other words, the logarithm of
x to base
b is the solution
y
of the equation
[2]
The logarithm is denoted "log
b(
x)" (pronounced as "the logarithm of
x to base
b" or
"the base-
b logarithm of
x"). In the equation
y = log
b(
x), the value
y is the answer
to the question "To what power must
b be raised, in order to yield
x?". For the
logarithm to be defined, the base
b must be a
positive real number not equal to
1 and
x must be a positive number.
[nb 2]