Answer :
To find \( f(1) \) in the given sequence, we can follow the recursive formula provided:
1. \( f(0) = -20 \) (given)
2. Using the recursive formula \( f(n) = f(n-1) - 5 \) for \( n \geq 1 \):
- \( f(1) = f(0) - 5 \)
- \( f(1) = -20 - 5 \)
- \( f(1) = -25 \)
Therefore, \( f(1) = -25 \).
