To find the function that determines the area of the circular layer of juice after \( t \) minutes, we start with the formula for the area of a circle:
\[ A(r) = \pi r^2 \]
Given that the radius \( r \) is increasing according to the function:
\[ r(t) = 8t \]
Now, we can substitute \( r(t) \) into the area function \( A(r) \):
\[ A(t) = A(r(t)) = A(8t) = \pi (8t)^2 \]
Calculating \( (8t)^2 \):
\[ (8t)^2 = 64t^2 \]
Therefore, the area function \( A(t) \) becomes:
\[ A(t) = \pi (64t^2) = 64\pi t^2 \]
So, the function that can be used to determine the area of the circular layer of juice after \( t \) minutes is:
\[ A(t) = 64\pi t^2 \]
Thus, the missing values that you need to fill in are:
- \( 64 \)
- \( \pi \)
- \( t^2 \)
This means the complete expression for the area is \( 64\pi t^2 \).