Trig Quadrant Iv
1. **Problem Statement:**
Given the terminal side of angle $\theta$ lies on the line $-4x + 3y = 0$ in Quadrant IV, find the values of $\sin \theta$, $\cos \theta$, $\tan \theta$, $\sec \theta$, and $\csc \theta$.
2. **Rewrite the line equation:**
From $-4x + 3y = 0$, solve for $y$:
$$3y = 4x \implies y = \frac{4}{3}x$$
3. **Determine the coordinates on the terminal side:**
Since the terminal side lies on this line, any point $(x,y)$ satisfies $y = \frac{4}{3}x$.
4. **Identify the quadrant and signs:**
Quadrant IV means $x > 0$ and $y < 0$.
5. **Adjust signs to fit Quadrant IV:**
Since $y = \frac{4}{3}x$ is positive for $x > 0$, to be in Quadrant IV where $y < 0$, we take $y = -\frac{4}{3}x$.
6. **Find the radius $r$ (distance from origin):**
$$r = \sqrt{x^2 + y^2} = \sqrt{x^2 + \left(-\frac{4}{3}x\right)^2} = \sqrt{x^2 + \frac{16}{9}x^2} = \sqrt{\frac{25}{9}x^2} = \frac{5}{3}|x|$$
Since $x > 0$, $|x| = x$, so:
$$r = \frac{5}{3}x$$
7. **Calculate trigonometric ratios:**
- $$\sin \theta = \frac{y}{r} = \frac{-\frac{4}{3}x}{\frac{5}{3}x} = -\frac{4}{5}$$
- $$\cos \theta = \frac{x}{r} = \frac{x}{\frac{5}{3}x} = \frac{3}{5}$$
- $$\tan \theta = \frac{y}{x} = -\frac{4}{3}$$
- $$\sec \theta = \frac{1}{\cos \theta} = \frac{1}{\frac{3}{5}} = \frac{5}{3} \approx 1.6667$$
- $$\csc \theta = \frac{1}{\sin \theta} = \frac{1}{-\frac{4}{5}} = -\frac{5}{4} = -1.25$$
8. **Convert to decimals as requested:**
- $\sin \theta = -0.8$
- $\cos \theta = 0.6$
- $\tan \theta = -1.3333$
- $\sec \theta = 1.6667$
- $\csc \theta = -1.25$
**Final answers:**
$$\sin \theta = -0.8$$
$$\cos \theta = 0.6$$
$$\tan \theta = -1.3333$$
$$\sec \theta = 1.6667$$
$$\csc \theta = -1.25$$