The equation $y = \cos(x)$ represents a cosine function, which is a periodic trigonometric function. Here are some key properties of the cosine function:

1. Domain: The function $y = \cos(x)$ is defined for all real numbers, so the domain is $(-\infty, \infty)$.

2. Range: The values of $y = \cos(x)$ are between -1 and 1, inclusive. Hence, the range is $[-1, 1]$.

3. Periodicity: The cosine function repeats its values every $2\pi$ units. So, the period of $y = \cos(x)$ is $2\pi$.

4. Amplitude: The amplitude of the cosine function is 1, which is the maximum distance from the horizontal axis to the peaks of the wave.

5. Key points: The function passes through several important points:

   • $\cos(0) = 1$
   • $\cos(\pi/2) = 0$
   • $\cos(\pi) = -1$
   • $\cos(3\pi/2) = 0$
   • $\cos(2\pi) = 1$

Would you like more details or have any specific questions?

Here are 5 related questions to explore:

1. What is the derivative of $y = \cos(x)$?
2. How do you find the integral of $y = \cos(x)$?
3. What transformations occur if you modify $y = \cos(x)$ to $y = 2\cos(x)$ or $y = \cos(x - \pi/4)$?
4. How does the graph of $y = \cos(x)$ compare to $y = \sin(x)$?
5. What are the real-world applications of the cosine function?

Tip: The cosine function describes oscillatory behavior, making it useful in modeling waves, sound, and circular motion.