Find the domain of the function.
-$$g ( x ) = \frac { 2 x } { x ^ { 2 } - 81 }$$
A) {x|x 81}
B) {x|x ≠-9, 9}
C) {x|x ≠ 0}
D) all real numbers

Question

Find the domain of the function.
-$$g ( x ) = \frac { 2 x } { x ^ { 2 } - 81 }$$
A) {x|x > 81}
B) {x|x ≠-9, 9}
C) {x|x ≠ 0}
D) all real numbers

Quizplus · Accepted Answer

The domain of $g(x) = \frac{2x}{x^2 - 81}$ excludes values of $x$ that make the denominator zero. Factoring the denominator gives $x^2 - 81 = (x - 9)(x + 9)$, so the function is undefined at $x = 9$ and $x = -9$. Thus, the domain is all real numbers except $x = 9$ and $x = -9$.

Find the Domain of the Function g(x)=2xx2−81g ( x ) = \frac { 2 x } { x ^ { 2 } - 81 }g(x)=x2−812x​

Find the Domain of the Function $g ( x ) = \frac { 2 x } { x ^ { 2 } - 81 }$