1. **State the problem:** We are given the height function of a basketball as a function of time: $$h(t) = -4.75t^2 + 8.75t + 1.5$$ for $$t \geq 0$$. We want to analyze this quadratic function to understand the basketball's height over time.
2. **Identify the type of function:** This is a quadratic function of the form $$h(t) = at^2 + bt + c$$ where $$a = -4.75$$, $$b = 8.75$$, and $$c = 1.5$$. Since $$a < 0$$, the parabola opens downward, meaning the basketball reaches a maximum height at the vertex.
3. **Find the vertex (maximum height):** The time at which the maximum height occurs is given by the vertex formula:
$$t = -\frac{b}{2a} = -\frac{8.75}{2 \times -4.75} = -\frac{8.75}{-9.5} = \frac{8.75}{9.5}$$
4. **Simplify the fraction:**
$$\frac{8.75}{9.5} = \frac{\cancel{8.75}}{\cancel{9.5}} = 0.9211$$ (approximate decimal)
5. **Calculate the maximum height:** Substitute $$t = 0.9211$$ into the height function:
$$h(0.9211) = -4.75(0.9211)^2 + 8.75(0.9211) + 1.5$$
6. **Calculate each term:**
$$-4.75 \times 0.8484 = -4.0309$$
$$8.75 \times 0.9211 = 8.0596$$
7. **Sum all terms:**
$$h(0.9211) = -4.0309 + 8.0596 + 1.5 = 5.5287$$ meters (approximate)
8. **Find the intercepts:**
- At $$t=0$$, $$h(0) = 1.5$$ meters (initial height).
- To find when the basketball hits the ground, solve $$h(t) = 0$$:
$$-4.75t^2 + 8.75t + 1.5 = 0$$
9. **Use quadratic formula:**
$$t = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} = \frac{-8.75 \pm \sqrt{8.75^2 - 4(-4.75)(1.5)}}{2(-4.75)}$$
10. **Calculate discriminant:**
$$8.75^2 = 76.5625$$
$$4 \times -4.75 \times 1.5 = -28.5$$
$$\sqrt{76.5625 - (-28.5)} = \sqrt{105.0625} = 10.25$$
11. **Calculate roots:**
$$t = \frac{-8.75 \pm 10.25}{-9.5}$$
12. **Calculate each root:**
$$t_1 = \frac{-8.75 + 10.25}{-9.5} = \frac{1.5}{-9.5} = -0.1579$$ (discard since $$t \geq 0$$)
$$t_2 = \frac{-8.75 - 10.25}{-9.5} = \frac{-19}{-9.5} = 2$$ seconds
13. **Interpretation:** The basketball starts at 1.5 meters, reaches a maximum height of approximately 5.53 meters at about 0.92 seconds, and hits the ground at 2 seconds.
**Final answer:**
- Maximum height: $$5.53$$ meters at $$t = 0.92$$ seconds
- Hits ground at $$t = 2$$ seconds
Basketball Height F5C690
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.