Questions: Find the limit L (if it exists). (If the limit is infinite, enter '∞' or '-', as appropriate. If the limit does not otherwise exist, enter DNE.)
lim(x -> 3^-) (x-3)/(x^2-9)
L=
Transcript text: Find the limit $L$ (if it exists). (If the limit is infinite, enter ' $\infty$ ' or '- ${ }^{\prime}$ ', as appropriate. If the limit does not otherwise exist, enter DNE.)
\[
\begin{array}{l}
\lim _{x \rightarrow 3^{-}} \frac{x-3}{x^{2}-9} \\
L=\square
\end{array}
\]
Solution
Solution Steps
To find the limit of the given function as \( x \) approaches 3 from the left, we first simplify the expression. The denominator can be factored as a difference of squares. After simplification, we evaluate the limit by substituting values approaching 3 from the left into the simplified expression.
Step 1: Simplifying the Function
We start with the limit expression:
\[
\lim_{x \rightarrow 3^{-}} \frac{x - 3}{x^2 - 9}
\]
The denominator can be factored as:
\[
x^2 - 9 = (x - 3)(x + 3)
\]
Thus, we can rewrite the function as:
\[
\frac{x - 3}{(x - 3)(x + 3)} = \frac{1}{x + 3} \quad \text{for } x \neq 3
\]
Step 2: Evaluating the Limit
Now, we evaluate the limit as \( x \) approaches 3 from the left:
\[
\lim_{x \rightarrow 3^{-}} \frac{1}{x + 3}
\]
Substituting \( x = 3 \):
\[
\frac{1}{3 + 3} = \frac{1}{6}
\]