1. **State the problem:** We need to find values of $a$ and $b$ such that the function
$$g(x) = \begin{cases} a^2 x + 2 & \text{if } x > 3 \\ 5 & \text{if } x = 3 \\ x^2 - b x + a & \text{if } x < 3 \end{cases}$$
is continuous at $x=3$.
2. **Recall the continuity condition:** For $g(x)$ to be continuous at $x=3$, the left-hand limit, right-hand limit, and the function value at $x=3$ must be equal:
$$\lim_{x \to 3^-} g(x) = g(3) = \lim_{x \to 3^+} g(x)$$
3. **Given limits:**
$$\lim_{x \to 3^-} f(x) = 2, \quad \lim_{x \to 3^+} f(x) = -1.5$$
4. **Apply continuity to $g(x)$:**
- Right-hand limit at $x=3$:
$$\lim_{x \to 3^+} g(x) = a^2 \cdot 3 + 2 = 3 a^2 + 2$$
- Left-hand limit at $x=3$:
$$\lim_{x \to 3^-} g(x) = 3^2 - 3 b + a = 9 - 3 b + a$$
- Function value at $x=3$:
$$g(3) = 5$$
5. **Set limits equal to function value for continuity:**
$$3 a^2 + 2 = 5$$
$$9 - 3 b + a = 5$$
6. **Solve the first equation:**
$$3 a^2 + 2 = 5 \implies 3 a^2 = 3 \implies a^2 = 1 \implies a = \pm 1$$
7. **Solve the second equation for $b$:**
$$9 - 3 b + a = 5 \implies -3 b = 5 - 9 - a = -4 - a \implies b = \frac{4 + a}{3}$$
8. **Substitute $a$ values:**
- If $a=1$, then
$$b = \frac{4 + 1}{3} = \frac{5}{3}$$
- If $a=-1$, then
$$b = \frac{4 - 1}{3} = \frac{3}{3} = 1$$
**Final answer:**
$$\boxed{(a,b) = (1, \frac{5}{3}) \text{ or } (-1, 1)}$$
Continuity Values 3C0761
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