Current in Discharing Capacitor

[05holtel]

Homework Statement

How do you express the current in a discharging capacitor.

I know that I = dQ/dt,

Qd = Q0e^(-t/RC)
I = d/dt (Q0e^(-t/RC))
= (Q/RC)e^(-t/RC)

I am confused because taking the derivative of Q0e^(-t/RC)) I think should be
(-Q/RC)e^(-t/RC) because the derivative of (-t/RC) is (-1/RC)

Which solution is correct
Thanks in advance

 

[jdc15]

Don't quote me on this but they may just be taking the absolute value for simplicity, since current can be taken as positive in one direction or negative to point in the other direction.