The base of ln is e, which is the abbreviation of loge (e is subscript);
The radix of logarithm can be any positive number other than 1.
In general, the function y = logax(a >；; 0, a≠ 1) is called logarithmic function, that is, a function with power (real number) as independent variable, exponent as dependent variable and radix as constant is called logarithmic function.
Where x is the independent variable and the function domain is (0, +∞), that is, x >；; 0。 It is actually the inverse function of exponential function, which can be expressed by x=ay. Therefore, the stipulation of a in exponential function is also applicable to logarithmic function.
"log" is the abbreviation of Latin logarithm, which is pronounced as [English ][l? π] [America ][l? lɑɡ]。 ɡ
Extended data:
Functional attribute
Solution of domain: the domain of logarithmic function y=logax is {xè x >; 0}, but when solving the domain of logarithmic compound function, we should not only pay attention to being greater than 0, but also pay attention to the fact that the base number is greater than 0 and not equal to 1. If the domain of function y=logx(2x- 1) is required, it must satisfy x >；; 0 and x≠ 1
And 2x-1>; 0, get x> 1/2 and x≠ 1, that is, its domain is {x丨 x >；; 1/2 and x≠ 1}
Range: real number set r, obviously the logarithmic function is unbounded;
Fixed point: the function image of logarithmic function always passes through the fixed point (1, 0);
Monotonicity: a> is at 1, which is a monotone increasing function on the definition domain;
When 0<a< 1, it is a monotonic decreasing function on the domain;
Parity: Non-odd non-even function
Periodicity: Not a periodic function.
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