1. **Problem:** A football player punts a ball. The path of the ball is modeled by the equation $$h = -0.004d^2 + d + 25$$ where $d$ is the horizontal distance in feet and $h$ is the height in feet. We need to find how far from the player the ball will land, i.e., when $h=0$.
2. **Formula and rules:** To find where the ball lands, set the height $h=0$ and solve the quadratic equation:
$$0 = -0.004d^2 + d + 25$$
We will use the quadratic formula:
$$d = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$
where $a = -0.004$, $b = 1$, and $c = 25$.
3. **Calculate the discriminant:**
$$\Delta = b^2 - 4ac = 1^2 - 4(-0.004)(25) = 1 + 0.4 = 1.4$$
4. **Apply the quadratic formula:**
$$d = \frac{-1 \pm \sqrt{1.4}}{2(-0.004)}$$
5. **Simplify denominator:**
$$2(-0.004) = -0.008$$
6. **Calculate roots:**
$$d_1 = \frac{-1 + \sqrt{1.4}}{-0.008}, \quad d_2 = \frac{-1 - \sqrt{1.4}}{-0.008}$$
7. **Evaluate square root:**
$$\sqrt{1.4} \approx 1.1832$$
8. **Calculate each root:**
$$d_1 = \frac{-1 + 1.1832}{-0.008} = \frac{0.1832}{-0.008} = -22.9$$
$$d_2 = \frac{-1 - 1.1832}{-0.008} = \frac{-2.1832}{-0.008} = 272.9$$
9. **Interpretation:** Distance cannot be negative, so the ball lands approximately at $$d = 272.9$$ feet from the player.
**Final answer:** The ball will land about **273 feet** from the football player.
Football Punt Distance 4F7839
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