Syntax: Log ( number )
numberAny positive number or expression that returns a positive number.
Data type returned: Number
Returns the base-10 logarithm of number.
Logarithms are used to determined the power to which a number must be raised to equal some other number. If xn = y, then n = Logx(y). The Log() function assumes a base (the variable x in the preceding formula) of 10. The Lg() function uses a base of 2, whereas the Ln() function uses a base of e.
The Log() and Lg() functions produce base-10 and base-2 logarithms, respectively. The Ln() function produces base-e logarithms, but it can also be used to solve a logarithm of any base. Log (base-x) of y is equivalent to Ln (y) / Ln (x).
Returns 0 because 10^0 = 1.
Returns 2 because 10^2 = 100.
Returns 3 because 10^3 = 1000.