We are given the function $f$, defined as:

1. $f(1) = 3$
2. $f(n) = f(n - 1) - 3$ for $n \geq 2$

We are tasked with finding the value of $f(4)$.

Step-by-step solution:

Using the recursive formula $f(n) = f(n-1) - 3$, we can calculate $f(2)$, $f(3)$, and $f(4)$.

Step 1: Find $f(2)$

Using $f(2) = f(1) - 3$: $f(2) = 3 - 3 = 0$

Step 2: Find $f(3)$

Using $f(3) = f(2) - 3$: $f(3) = 0 - 3 = -3$

Step 3: Find $f(4)$

Using $f(4) = f(3) - 3$: $f(4) = -3 - 3 = -6$

Thus, the value of $f(4)$ is $\boxed{-6}$.

Would you like a detailed explanation of any part of the solution? Here are five related questions to explore this concept further:

1. How can we generalize the recursive function for any $n$?
2. What is the pattern of the values for $f(n)$ as $n$ increases?
3. How would the function change if the recursive step was $f(n) = f(n-1) - 2$?
4. What are the advantages of defining functions recursively versus explicitly?
5. Can we solve this problem using an explicit formula for $f(n)$?

Tip: In recursive sequences, it's useful to compute a few terms to identify any pattern before attempting a general solution.