Write the domain in interval notation.
-$$f ( x ) = \log _ { 3 } \left( x ^ { 2 } - 9 \right)$$
A) $( - \infty , \infty )$
B) $( - \infty , 3 ) \cup ( 3 , \infty )$
C) $( - \infty , - 3 ) \cup ( 3 , \infty )$
D) $( - 3,3 )$

Question

Quizplus · Accepted Answer

The argument of the logarithm, $x^2 - 9$, must be greater than 0. Factoring gives $(x + 3)(x - 3) > 0$, which is true for $x < -3$ and $x > 3$. Thus, the domain is $( - \infty , - 3 ) \cup ( 3 , \infty )$.

Write the Domain in Interval Notation f(x)=log⁡3(x2−9)f ( x ) = \log _ { 3 } \left( x ^ { 2 } - 9 \right)f(x)=log3​(x2−9)

Write the Domain in Interval Notation $f ( x ) = \log _ { 3 } \left( x ^ { 2 } - 9 \right)$