To find the current \( I \) at which the voltage \( V \) is minimized, we first compute the derivative of \( V \) with respect to \( I \):
\[
\frac{dV}{dI} = 6I + 6
\]
Setting the derivative equal to zero to find the critical points:
\[
6I + 6 = 0 \implies I = -1
\]
Step 2: Calculating the Minimum Voltage
Next, we substitute the critical point \( I = -1 \) back into the original voltage equation:
\[
V = 3(-1)^2 + 6(-1) - 2 = 3 - 6 - 2 = -5
\]
Final Answer
The minimum current is \( I = -1 \) and the minimum voltage is \( V = -5 \). Thus, the answers are:
\[
\boxed{I = -1}
\]
\[
\boxed{V = -5}
\]