Log (c) (a/b) = log (c) a/log (c) b-equivalent to power division with the same radix, and exponential subtraction with the same radix.
2.log(c)(a n)= n * log(c)a- is equivalent to a power, and the radix is unchanged.
Log(c m)(a n)=(n/m)log(c)a—— the more general case of the above formula (which can be derived from the above formula and the formula for changing the bottom).
3.log(c)a = log(b)a/log(b)c- bottoming formula
The above are several common formulas of logarithm.
But the most important thing is to understand the meaning of logarithms-if c n = a, then n = log (c) a-the essence of logarithms is the operation of knowing the base and power results to find the exponent.