It looks like you're trying to write the equation of a trigonometric function based on the cosine function. However, your equation seems incomplete.

A general cosine function follows this form:
$y = A \cos(Bx + C) + D$ where:

• $A$ is the amplitude (vertical stretch/shrink).
• $B$ affects the period ($\frac{2\pi}{B}$).
• $C$ shifts the graph horizontally (phase shift).
• $D$ shifts the graph vertically.

If your equation is something like:
$y = \cos(x) + C$ then $C$ represents a vertical shift.

Could you clarify the missing part so I can give you the exact equation? Also, do you have a graph to analyze?

Related Questions:

1. How do phase shifts affect the cosine graph?
2. What is the period of a cosine function, and how do we calculate it?
3. How does changing the amplitude affect the graph of $y = \cos(x)$?
4. What happens if we add a sine term to the cosine function?
5. How can we determine the equation from a given trigonometric graph?

Tip: The cosine function starts at its maximum value when $x = 0$, unlike the sine function, which starts at zero.