Evaluate the given function.
-$$f ( x ) = \log _ { 3 } x , f ( 81 )$$
A) $- 4$
B) 3
C) $- 3$
D) 4

Question

Evaluate the given function.  
-$$f ( x ) = \log _ { 3 } x , f ( 81 )$$
A) $- 4$ 
B) 3 
C) $- 3$ 
D) 4

Quizplus · Accepted Answer

We have to evaluate $f(81)$, which means we need to plug in 81 for x in the function $f(x)=\log_3x$. Using the definition of logarithms, we know that $\log_3 81$ is the exponent to which we raise 3 to get 81. In other words, $\log_3 81 = 4$, since $3^4 = 81$. Therefore, $f(81) = \log_3 81 = 4$. So the answer is D.

Evaluate the Given Function f(x)=log⁡3x,f(81)f ( x ) = \log _ { 3 } x , f ( 81 )f(x)=log3​x,f(81)

Evaluate the Given Function $f ( x ) = \log _ { 3 } x , f ( 81 )$