1. **Problem statement:** Find the values of $a$ and $b$ such that the function
$$
f(x) = \begin{cases}
-2, & x \leq -1 \\
ax - b, & -1 < x < 1 \\
3, & x \geq 1
\end{cases}
$$
is continuous everywhere.
2. **Continuity condition:** A function is continuous at a point if the left-hand limit, right-hand limit, and the function value at that point are all equal.
3. **Check continuity at $x = -1$:**
- Left limit: $\lim_{x \to -1^-} f(x) = -2$
- Right limit: $\lim_{x \to -1^+} f(x) = a(-1) - b = -a - b$
- Function value: $f(-1) = -2$
Set left and right limits equal for continuity:
$$
-2 = -a - b
$$
4. **Check continuity at $x = 1$:**
- Left limit: $\lim_{x \to 1^-} f(x) = a(1) - b = a - b$
- Right limit: $\lim_{x \to 1^+} f(x) = 3$
- Function value: $f(1) = 3$
Set left and right limits equal for continuity:
$$
a - b = 3
$$
5. **Solve the system of equations:**
$$
\begin{cases}
-2 = -a - b \\
3 = a - b
\end{cases}
$$
Add the two equations:
$$
-2 + 3 = (-a - b) + (a - b) \implies 1 = -2b \implies b = -\frac{1}{2}
$$
Substitute $b = -\frac{1}{2}$ into $3 = a - b$:
$$
3 = a - \left(-\frac{1}{2}\right) = a + \frac{1}{2} \implies a = 3 - \frac{1}{2} = \frac{5}{2}
$$
6. **Final answer:**
$$
a = \frac{5}{2}, \quad b = -\frac{1}{2}
$$
These values make $f(x)$ continuous everywhere.
Continuity Values 60465B
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