(3) Are the following signals energy signal or power signal 1) \( f(t)=e^{-t} \cos t, t \geq 0 \) 2) \( f(t)=2 t+1,-1 \leq t \leq 2 \) 3) \( f(k)=\left(\frac{4}{5}\right)^{k}, k \geq 0 \) 4) \( f(k)=e