Question: (a) Find the domain of the following function.
(b) Locate any intercepts.
(c) Graph the function.
(d) Based on the graph, find the range.
f(x) = { x² if 0
1. **State the problem:** We have a piecewise function:
$$f(x) = \begin{cases} x^2 & \text{if } 0 < x \leq 5 \\ 5x & \text{if } 5 < x < 8 \\ 40 & \text{if } x \geq 8 \end{cases}$$
We need to find the domain, intercepts, graph it, and find the range.
2. **Find the domain:**
The domain is all $x$ values for which $f(x)$ is defined.
- For $x^2$, domain is $0 < x \leq 5$
- For $5x$, domain is $5 < x < 8$
- For $40$, domain is $x \geq 8$
Combining these, the domain is:
$$\boxed{(0, \infty)}$$
3. **Locate intercepts:**
- **x-intercepts:** Solve $f(x) = 0$
For $x^2 = 0$, $x=0$ but $x=0$ is not in domain (since $0 < x$), so no intercept here.
For $5x=0$, $x=0$ but $0$ not in domain for this piece.
For $40=0$, no solution.
So no x-intercepts.
- **y-intercept:** $f(0)$ is undefined (since domain excludes $0$), so no y-intercept.
4. **Graph the function:**
- From $0 < x \leq 5$, graph $y = x^2$ starting just right of $0$ (open circle at $x=0$) up to and including $(5, 25)$ (closed circle).
- From $5 < x < 8$, graph $y = 5x$ starting just right of $5$ (open circle at $(5, 25)$) to just left of $8$ (open circle at $(8, 40)$).
- For $x \geq 8$, graph horizontal line $y=40$ starting at $(8, 40)$ (closed circle) extending right.
5. **Find the range:**
- From $0 < x \leq 5$, $y = x^2$ ranges from just above $0$ to $25$.
- From $5 < x < 8$, $y = 5x$ ranges from just above $25$ to just below $40$.
- For $x \geq 8$, $y=40$ constant.
Combining, the range is:
$$\boxed{(0, 40]}$$
**Final answers:**
- Domain: $(0, \infty)$
- No intercepts
- Range: $(0, 40]$