1. **State the problem:**
We have a right triangle with sides $x=9$, $y=6$, and hypotenuse $z$. We need to find $\cos(\theta)$, $\sin(\theta)$, and $\tan(\theta)$ as exact fractions.
2. **Formula and rules:**
For a right triangle with angle $\theta$:
- $\cos(\theta) = \frac{\text{adjacent side}}{\text{hypotenuse}}$
- $\sin(\theta) = \frac{\text{opposite side}}{\text{hypotenuse}}$
- $\tan(\theta) = \frac{\text{opposite side}}{\text{adjacent side}}$
3. **Find the hypotenuse $z$ using the Pythagorean theorem:**
$$
z = \sqrt{x^2 + y^2} = \sqrt{9^2 + 6^2} = \sqrt{81 + 36} = \sqrt{117}
$$
4. **Simplify $\sqrt{117}$:**
$$
\sqrt{117} = \sqrt{9 \times 13} = 3\sqrt{13}
$$
5. **Calculate $\cos(\theta)$:**
Since $\theta$ is at the bottom-right corner, the adjacent side to $\theta$ is $x=9$ and the hypotenuse is $z=3\sqrt{13}$.
$$
\cos(\theta) = \frac{9}{3\sqrt{13}} = \frac{\cancel{9}}{\cancel{3}\sqrt{13}} = \frac{3}{\sqrt{13}}
$$
6. **Rationalize the denominator for $\cos(\theta)$:**
$$
\cos(\theta) = \frac{3}{\sqrt{13}} \times \frac{\sqrt{13}}{\sqrt{13}} = \frac{3\sqrt{13}}{13}
$$
7. **Calculate $\sin(\theta)$:**
The opposite side to $\theta$ is $y=6$.
$$
\sin(\theta) = \frac{6}{3\sqrt{13}} = \frac{\cancel{6}}{\cancel{3}\sqrt{13}} = \frac{2}{\sqrt{13}}
$$
8. **Rationalize the denominator for $\sin(\theta)$:**
$$
\sin(\theta) = \frac{2}{\sqrt{13}} \times \frac{\sqrt{13}}{\sqrt{13}} = \frac{2\sqrt{13}}{13}
$$
9. **Calculate $\tan(\theta)$:**
$$
\tan(\theta) = \frac{\text{opposite}}{\text{adjacent}} = \frac{6}{9} = \frac{2}{3}
$$
**Final answers:**
- $\cos(\theta) = \frac{3\sqrt{13}}{13}$
- $\sin(\theta) = \frac{2\sqrt{13}}{13}$
- $\tan(\theta) = \frac{2}{3}$
Trig Ratios 3F7A96
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