Limits True False
1. **Problem 1: Determine the truth of limit statements for the function $y=f(x)$ given the graph.**
- The graph is piecewise linear with points: $(-1,-1)$ solid, $(0,0)$ open, $(1,1)$ open, $(2,1)$ solid.
- Lines connect $(-1,-1)$ to $(0,0)$, $(0,0)$ to $(1,1)$, and $(1,1)$ to $(2,1)$.
**Step 1:** Analyze $\lim_{x \to 0} f(x)$.
- From the left, as $x \to 0^-$, $f(x) \to 0$.
- From the right, as $x \to 0^+$, $f(x) \to 0$.
- Both sides approach 0, so $\lim_{x \to 0} f(x) = 0$.
**Step 2:** Analyze $\lim_{x \to 1} f(x)$.
- From the left, as $x \to 1^-$, $f(x) \to 1$.
- From the right, as $x \to 1^+$, $f(x) \to 1$.
- Both sides approach 1, so $\lim_{x \to 1} f(x) = 1$.
**Step 3:** Check if $\lim_{x \to x_0} f(x)$ exists for every $x_0 \in (-1,1)$.
- The function is linear and continuous between points except at $x=0$ and $x=1$ where there are open circles.
- However, limits depend on approaching values, not function value at the point.
- Since the graph is continuous (no jumps) in $(-1,1)$, limits exist at every $x_0$ in $(-1,1)$.
**Step 4:** Evaluate each statement:
- a. $\lim_{x \to 0} f(x)$ exists: **True**.
- b. $\lim_{x \to 0} f(x) = 0$: **True**.
- c. $\lim_{x \to 0} f(x) = 1$: **False**.
- d. $\lim_{x \to 1} f(x) = 1$: **True**.
- e. $\lim_{x \to 1} f(x) = 0$: **False**.
- f. $\lim_{x \to x_0} f(x)$ exists for every $x_0 \in (-1,1)$: **True**.
2. **Problem 2: Explain why $\lim_{x \to 0} \frac{x}{|x|}$ does not exist.**
**Step 1:** Consider the left-hand limit as $x \to 0^-$:
- For $x<0$, $|x| = -x$, so
$$\frac{x}{|x|} = \frac{x}{-x} = -1.$$
- Thus, $\lim_{x \to 0^-} \frac{x}{|x|} = -1$.
**Step 2:** Consider the right-hand limit as $x \to 0^+$:
- For $x>0$, $|x| = x$, so
$$\frac{x}{|x|} = \frac{x}{x} = 1.$$
- Thus, $\lim_{x \to 0^+} \frac{x}{|x|} = 1$.
**Step 3:** Since the left-hand and right-hand limits are not equal,
$$\lim_{x \to 0} \frac{x}{|x|}$$
**does not exist**.
**Final answers:**
- Q1: a) True, b) True, c) False, d) True, e) False, f) True.
- Q2: The limit does not exist because the left and right limits are different: $-1$ and $1$ respectively.