A3. What is the initial value of the exponential function $f(x)=-2 \cdot 2^{5 x-1}+4$?
(A) 4
(B) 5
(C) 3
(D) -2
(E) 0
A3. To calculate the initial value, we substitute $x=0$ and compute the function value $f(0)=-2 \cdot 2^{5 \cdot 0-1}+4=-2 \cdot 2^{-1}+4=3$.