1. **State the problem:** We need to find the sum of the vectors $\langle 1, -2 \rangle$ and $\langle 1, 8 \rangle$, then find the magnitude and direction of the resultant vector. Round angles to the nearest degree and other values to the nearest tenth.
2. **Add the vectors:**
$$\langle 1, -2 \rangle + \langle 1, 8 \rangle = \langle 1+1, -2+8 \rangle = \langle 2, 6 \rangle$$
3. **Find the magnitude of the resultant vector:**
The magnitude formula is:
$$\text{magnitude} = \sqrt{x^2 + y^2}$$
where $x=2$ and $y=6$.
Calculate:
$$\sqrt{2^2 + 6^2} = \sqrt{4 + 36} = \sqrt{40}$$
Simplify:
$$\sqrt{40} = \sqrt{4 \times 10} = 2\sqrt{10} \approx 6.3$$
4. **Find the direction (angle) of the resultant vector:**
The direction $\theta$ is given by:
$$\theta = \tan^{-1}\left(\frac{y}{x}\right) = \tan^{-1}\left(\frac{6}{2}\right) = \tan^{-1}(3)$$
Calculate:
$$\theta \approx 71.6^\circ$$
Rounded to the nearest degree:
$$72^\circ$$
5. **Summary:**
- Resultant vector: $\langle 2, 6 \rangle$
- Magnitude: $6.3$
- Direction: $72^\circ$
**Note:** None of the provided options match this result exactly, so the correct resultant vector and its magnitude and direction are as calculated above.
Vector Sum 17C23B
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