Let \( f(x)=\frac{x-8}{x^{2}-8 x} \). Find the indicated quantities, if they exist. \( \begin{array}{lll}\text { (A) } \lim _{x \rightarrow 0} f(x) & \text { (B) } \lim _{x \rightarrow 8} f(x) & \text { (C) } \lim _{x \rightarrow 64} f(x)\end{array} \) A) Select the correct choice below and, if necessery, fill in the answer box to complete your choice: A. \( \lim _{x \rightarrow 0} \frac{x-8}{x^{2}-8 x}=\square \) (Type an integer or a simplified fraction.) B. The limit does not exist
Real Tutor Solution
Answer
Solution
Reviewed and approved by the UpStudy tutoring team
Mind Expander
To evaluate the limits of the function \( f(x)=\frac{x-8}{x^{2}-8 x} \), we can simplify the function first. Notice that the denominator can be factored: \[ f(x) = \frac{x-8}{x(x-8)} \] This simplifies to: \[ f(x) = \frac{1}{x} \quad \text{for } x \neq 8 \] Now we can proceed with each limit. **(A)** For \( \lim _{x \rightarrow 0} f(x) \): Substituting \( x = 0 \) into the simplified expression gives us: \[ \lim_{x \to 0} f(x) = \lim_{x \to 0} \frac{1}{x} \] As \( x \) approaches \( 0 \), \( \frac{1}{x} \) approaches \( \infty \). Therefore: A. \( \lim_{x \rightarrow 0} \frac{x-8}{x^{2}-8 x}=\infty \) --- **(B)** For \( \lim _{x \rightarrow 8} f(x) \): Since the function is not defined at \( x = 8 \), we must check the limit as we approach 8. The simplified function gives us: \[ \lim_{x \to 8} f(x) = \lim_{x \to 8} \frac{1}{x} \] So, substituting \( x = 8 \): \[ \lim_{x \to 8} f(x) = \frac{1}{8} \] Thus, the answer for B is: B. \( \lim_{x \rightarrow 8} f(x) = \frac{1}{8} \) --- **(C)** For \( \lim _{x \rightarrow 64} f(x) \): Again, using the simplified expression: \[ \lim_{x \to 64} f(x) = \lim_{x \to 64} \frac{1}{x} \] Substituting \( x = 64 \): \[ \lim_{x \to 64} f(x) = \frac{1}{64} \] Thus, the answer for C is: C. \( \lim_{x \rightarrow 64} f(x) = \frac{1}{64} \) --- In summary: A. \( \infty \) B. \( \frac{1}{8} \) C. \( \frac{1}{64} \)