Question: Given the function $C(t) = (t - 1)(t + 5)(t - 4)$
Remember that intercepts are points on a graph and must be given in coordinate form.
Its C-intercept is
Its t-intercept(s) is/are
1. **State the problem:** Find the $C$-intercept and the $t$-intercepts of the function $$C(t) = (t - 1)(t + 5)(t - 4).$$
2. **Recall definitions:**
- The $C$-intercept is the point where the graph crosses the $C$-axis (vertical axis), which occurs when $t=0$.
- The $t$-intercepts are the points where the graph crosses the $t$-axis (horizontal axis), which occur when $C(t) = 0$.
3. **Find the $C$-intercept:**
Substitute $t=0$ into the function:
$$C(0) = (0 - 1)(0 + 5)(0 - 4) = (-1)(5)(-4) = 20.$$
So the $C$-intercept is at the point $(0, 20)$.
4. **Find the $t$-intercepts:**
Set $C(t) = 0$:
$$(t - 1)(t + 5)(t - 4) = 0.$$
This product is zero if any factor is zero:
- $t - 1 = 0 \implies t = 1$
- $t + 5 = 0 \implies t = -5$
- $t - 4 = 0 \implies t = 4$
So the $t$-intercepts are at points $(1, 0)$, $(-5, 0)$, and $(4, 0)$.
**Final answer:**
- $C$-intercept: $(0, 20)$
- $t$-intercepts: $(1, 0)$, $(-5, 0)$, $(4, 0)$