Identify the function for which you need to find the derivative: \( f(t) = \sec(4t + 5) \).
Recall the derivative rule for the secant function: if \( f(x) = \sec(u) \), then \( f'(x) = \sec(u) \tan(u) \cdot u' \), where \( u \) is a function of \( x \).
In this problem, \( u = 4t + 5 \). First, find the derivative of \( u \) with respect to \( t \), which is \( u' = \frac{d}{dt}(4t + 5) = 4 \).
Apply the chain rule: the derivative of \( f(t) = \sec(4t + 5) \) is \( f'(t) = \sec(4t + 5) \tan(4t + 5) \cdot 4 \).
Simplify the expression to get the final derivative: \( f'(t) = 4 \sec(4t + 5) \tan(4t + 5) \).