Eliminate Parameter
1. The problem is to eliminate the parameter $0$ from the parametric equations:
$$x = 3 \cos 0 - 5 \sin 0$$
$$y = 4 \sin 0 + 5 \cos 0$$
2. Note that $0$ here represents the parameter (angle), so we can rename it as $\theta$ for clarity:
$$x = 3 \cos \theta - 5 \sin \theta$$
$$y = 4 \sin \theta + 5 \cos \theta$$
3. The goal is to express $y$ solely in terms of $x$ by eliminating $\theta$.
4. Write the system:
$$x = 3 \cos \theta - 5 \sin \theta$$
$$y = 4 \sin \theta + 5 \cos \theta$$
5. Solve for $\cos \theta$ and $\sin \theta$ from these equations.
Multiply the first equation by 4 and the second by 3:
$$4x = 12 \cos \theta - 20 \sin \theta$$
$$3y = 12 \sin \theta + 15 \cos \theta$$
6. Rearrange to isolate $\cos \theta$ and $\sin \theta$:
Multiply original equations:
$$x = 3 \cos \theta - 5 \sin \theta$$
$$y = 4 \sin \theta + 5 \cos \theta$$
We can use a system approach or try to express $\cos \theta$ and $\sin \theta$ as:
From the first equation:
$$3 \cos \theta = x + 5 \sin \theta$$
From the second equation:
$$5 \cos \theta = y - 4 \sin \theta$$
Multiply the first equation by 5:
$$15 \cos \ theta = 5x + 25 \sin \theta$$
Multiply the second equation by 3:
$$15 \cos \theta = 3y - 12 \sin \theta$$
Set equal:
$$5x + 25 \sin \theta = 3y - 12 \sin \theta$$
Combine $\sin \theta$:
$$25 \sin \theta + 12 \sin \theta = 3y - 5x$$
$$37 \sin \theta = 3y - 5x$$
So:
$$\sin \theta = \frac{3y - 5x}{37}$$
Similarly substitute back into $3 \cos \theta = x + 5 \sin \theta$:
$$3 \cos \theta = x + 5 \times \frac{3y - 5x}{37} = x + \frac{15y - 25x}{37} = \frac{37x + 15y - 25x}{37} = \frac{12x + 15y}{37}$$
Therefore:
$$\cos \theta = \frac{12x + 15y}{111}$$
7. Using identity $\sin^2 \theta + \cos^2 \theta = 1$:
$$\left(\frac{3y - 5x}{37}\right)^2 + \left(\frac{12x + 15y}{111}\right)^2 = 1$$
Multiply both sides by $111^2$ (since $111 = 3 \times 37$):
$$ (3y - 5x)^2 + \left(\frac{12x + 15y}{3}\right)^2 = 111^2$$
Square terms and simplify carefully gives the Cartesian equation relating $x$ and $y$ without $\theta$.
**Final Cartesian relation:**
$$\left(\frac{3y - 5x}{37}\right)^2 + \left(\frac{12x + 15y}{111}\right)^2 = 1$$