1. **State the problem:** We have two complex numbers represented as vectors in the plane:
- $z_2$ with magnitude 8 and angle $\theta$ from the negative x-axis (second quadrant).
- $z_1$ with magnitude 4 and angle $\theta$ from the positive x-axis (fourth quadrant).
We want to find the ratio $\frac{z_1}{z_2}$.
2. **Express the complex numbers in polar form:**
- Since $z_2$ is in the second quadrant with angle $\theta$ from the negative x-axis, its angle from the positive x-axis is $\pi - \theta$. So,
$$z_2 = 8(\cos(\pi - \theta) + i\sin(\pi - \theta))$$
- Since $z_1$ is in the fourth quadrant with angle $\theta$ from the positive x-axis, its angle is $-\theta$ (measured clockwise). So,
$$z_1 = 4(\cos(-\theta) + i\sin(-\theta))$$
3. **Formula for division of complex numbers in polar form:**
$$\frac{z_1}{z_2} = \frac{r_1}{r_2} \left( \cos(\alpha_1 - \alpha_2) + i \sin(\alpha_1 - \alpha_2) \right)$$
where $r_1, r_2$ are magnitudes and $\alpha_1, \alpha_2$ are arguments (angles) of $z_1$ and $z_2$ respectively.
4. **Calculate the magnitude ratio:**
$$\frac{r_1}{r_2} = \frac{4}{8} = \frac{\cancel{4}}{\cancel{8}} = \frac{1}{2}$$
5. **Calculate the angle difference:**
$$\alpha_1 - \alpha_2 = (-\theta) - (\pi - \theta) = -\theta - \pi + \theta = -\pi$$
6. **Write the ratio:**
$$\frac{z_1}{z_2} = \frac{1}{2} \left( \cos(-\pi) + i \sin(-\pi) \right)$$
7. **Evaluate trigonometric functions:**
- $\cos(-\pi) = \cos(\pi) = -1$
- $\sin(-\pi) = -\sin(\pi) = 0$
So,
$$\frac{z_1}{z_2} = \frac{1}{2}(-1 + 0i) = -\frac{1}{2}$$
**Final answer:**
$$\boxed{\frac{z_1}{z_2} = -\frac{1}{2}}$$
Complex Ratio A4Efc6
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