The image you uploaded contains the function:

$f(x) = \cos^4(x)$

This represents the cosine of $x$ raised to the fourth power. If you'd like, I can help with evaluating this function, finding its derivatives, or performing other related tasks. Please let me know how you'd like to proceed.

Do you need further details or have any questions about this function?

Here are some related questions:

1. How do you differentiate $f(x) = \cos^4(x)$?
2. How do you integrate $f(x) = \cos^4(x)$?
3. What are the critical points of $f(x) = \cos^4(x)$?
4. How do you graph $f(x) = \cos^4(x)$?
5. What is the behavior of $f(x) = \cos^4(x)$ as $x \to \infty$?

Tip: When dealing with powers of trigonometric functions like $\cos^n(x)$, it's useful to look for trigonometric identities or simplify the expression using trigonometric properties before performing operations like differentiation or integration.