Answer:
B) [tex]log_3 81=4[/tex]
Step-by-step explanation:
The definition of logarithm is the following:
The logarithm of a certain number x with respect to a certain base b is the exponent by which b should be raised in order to give x. Mathematically, given the equation
[tex]b^y = x[/tex] (1)
The logarithm of x to base b is defined as
[tex]y=log_b x[/tex] (2)
In this problem, we have the following equation:
[tex]3^4=81[/tex]
By comparing it with equation (1), we notice that:
b = 3
y = 4
x = 81
Therefore, by re-arranging the variables using equation (2), we can rewrite it as:
[tex]4=log_3 81[/tex]
Which corresponds to option B.