The cosine function, $\cos(x)$, is periodic with a period of $2\pi$ and it oscillates between -1 and 1. Here are some key points on the graph of $\cos(x)$ between $0$ and $2\pi$:

1. $x = 0$: $\cos(0) = 1$.
2. $x = \frac{\pi}{2}$: $\cos\left(\frac{\pi}{2}\right) = 0$.
3. $x = \pi$: $\cos(\pi) = -1$.
4. $x = \frac{3\pi}{2}$: $\cos\left(\frac{3\pi}{2}\right) = 0$.
5. $x = 2\pi$: $\cos(2\pi) = 1$.

These points are critical values where the function changes its direction or reaches its maximum/minimum values.

Relative Questions:

1. What is the period of the $\cos(x)$ function?
2. How do you find the amplitude of $\cos(x)$?
3. What is the general formula for the maximum and minimum values of $\cos(x)$?
4. How does the graph of $\cos(x)$ compare to $\sin(x)$?
5. What are the intercepts of the $\cos(x)$ graph?

Tip: Remember, the $\cos(x)$ function is an even function, meaning $\cos(-x) = \cos(x)$, which reflects its symmetry about the y-axis.