Piecewise Continuity 569Ef2
1. **State the problem:** We are given a piecewise function:
$$f(x) = \begin{cases} x + 1 & \text{if } x < 4 \\ (x - 4)^2 + 3 & \text{if } x \geq 4 \end{cases}$$
We want to analyze this function, typically checking continuity and behavior at the breakpoint $x=4$.
2. **Check continuity at $x=4$:**
- The left-hand limit as $x$ approaches 4 is $\lim_{x \to 4^-} f(x) = 4 + 1 = 5$.
- The right-hand limit as $x$ approaches 4 is $\lim_{x \to 4^+} f(x) = (4 - 4)^2 + 3 = 0 + 3 = 3$.
- The function value at $x=4$ is $f(4) = 3$.
3. **Interpretation:**
Since the left-hand limit (5) does not equal the right-hand limit and the function value (3), the function is **not continuous** at $x=4$.
4. **Graph shape:**
- For $x<4$, the graph is a straight line with slope 1 and y-intercept 1.
- For $x \geq 4$, the graph is a parabola opening upwards with vertex at $(4,3)$.
5. **Summary:**
The function has a jump discontinuity at $x=4$ because the two pieces do not meet at the same value.
**Final answer:** The function $f(x)$ is not continuous at $x=4$ because $\lim_{x \to 4^-} f(x) \neq \lim_{x \to 4^+} f(x)$.