1. **State the problem:** We have the height function of an object launched from a platform given by $$f(x) = -16x^2 + 64x + 6$$ where $x$ is time in seconds and $f(x)$ is height in feet. We need to determine which statements A to E are true.
2. **Recall the quadratic formula and properties:** The function is a quadratic with $a = -16$, $b = 64$, and $c = 6$. Since $a < 0$, the parabola opens downward, so it has a maximum point.
3. **Find the height at 1 second (for statement A):**
$$f(1) = -16(1)^2 + 64(1) + 6 = -16 + 64 + 6 = 54$$
Since 54 is less than 60, statement A is false.
4. **Find the time of maximum height (for statement B):**
The vertex time is given by $$x = -\frac{b}{2a} = -\frac{64}{2 \times (-16)} = -\frac{64}{-32} = 2$$
So the object reaches maximum height at 2 seconds, statement B is true.
5. **Find the maximum height (for statement C):**
Calculate $$f(2) = -16(2)^2 + 64(2) + 6 = -16(4) + 128 + 6 = -64 + 128 + 6 = 70$$
The maximum height is 70 feet, so statement C is true.
6. **Height of the platform (for statement D):**
The height at time zero is the platform height:
$$f(0) = -16(0)^2 + 64(0) + 6 = 6$$
So the platform height is 6 feet, statement D is true.
7. **Height behavior over time (for statement E):**
Since the parabola opens downward, the height increases until the vertex at 2 seconds, then decreases afterward. So statement E is true.
**Final answers:**
- A: False
- B: True
- C: True
- D: True
- E: True
Quadratic Trajectory 25E432
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