Trig Function Values
1. **State the problem:** Given $\cos \theta = \frac{6}{10} = 0.6$ and $\tan \theta < 0$, find the values of $\sin \theta$, $\tan \theta$, $\csc \theta$, $\sec \theta$, and $\cot \theta$.
2. **Recall the Pythagorean identity:**
$$\sin^2 \theta + \cos^2 \theta = 1$$
This allows us to find $\sin \theta$ when $\cos \theta$ is known.
3. **Find $\sin \theta$:**
$$\sin^2 \theta = 1 - \cos^2 \theta = 1 - (0.6)^2 = 1 - 0.36 = 0.64$$
$$\sin \theta = \pm \sqrt{0.64} = \pm 0.8$$
4. **Determine the sign of $\sin \theta$ using $\tan \theta < 0$:**
Since $\tan \theta = \frac{\sin \theta}{\cos \theta}$ and $\cos \theta = 0.6 > 0$, for $\tan \theta$ to be negative, $\sin \theta$ must be negative.
Therefore, $\sin \theta = -0.8$.
5. **Calculate $\tan \theta$:**
$$\tan \theta = \frac{\sin \theta}{\cos \theta} = \frac{-0.8}{0.6} = -\frac{4}{3} \approx -1.3333$$
6. **Calculate $\csc \theta$ (reciprocal of $\sin \theta$):**
$$\csc \theta = \frac{1}{\sin \theta} = \frac{1}{-0.8} = -\frac{5}{4} = -1.25$$
7. **Calculate $\sec \theta$ (reciprocal of $\cos \theta$):**
$$\sec \theta = \frac{1}{\cos \theta} = \frac{1}{0.6} = \frac{5}{3} \approx 1.6667$$
8. **Calculate $\cot \theta$ (reciprocal of $\tan \theta$):**
$$\cot \theta = \frac{1}{\tan \theta} = \frac{1}{-\frac{4}{3}} = -\frac{3}{4} = -0.75$$
**Final answers:**
- $\sin \theta = -0.8$
- $\tan \theta = -\frac{4}{3}$
- $\csc \theta = -\frac{5}{4}$
- $\sec \theta = \frac{5}{3}$
- $\cot \theta = -\frac{3}{4}$