1. **State the problem:** A hockey player is aiming at a goalie net with posts 2.0 m apart. The player is 7.0 m from one post and 8.2 m from the other post. We need to find the angle within which the player must shoot the puck to get it in the net.
2. **Identify the triangle and angle:** The player and the two posts form a triangle with sides 7.0 m, 8.2 m, and 2.0 m. We want to find the angle at the player's position between the two posts.
3. **Use the Law of Cosines:** For a triangle with sides $a$, $b$, and $c$, and angle $\theta$ opposite side $c$, the law states:
$$\cos(\theta) = \frac{a^2 + b^2 - c^2}{2ab}$$
Here, $a=7.0$, $b=8.2$, and $c=2.0$ (distance between posts).
4. **Calculate $\cos(\theta)$:**
$$\cos(\theta) = \frac{7.0^2 + 8.2^2 - 2.0^2}{2 \times 7.0 \times 8.2} = \frac{49 + 67.24 - 4}{114.8} = \frac{112.24}{114.8}$$
5. **Simplify fraction:**
$$\cos(\theta) = \frac{\cancel{112.24}}{\cancel{114.8}} \approx 0.9779$$
6. **Find angle $\theta$:**
$$\theta = \arccos(0.9779) \approx 12.0^\circ$$
7. **Interpretation:** The player must shoot within an angle of approximately $12.0^\circ$ to get the puck between the posts.
**Final answer:** The shooting angle is about $12.0^\circ$.
Shooting Angle Ddd269
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