IsaacPhysics Discharging a Capacitor help

Having trouble solving this (https://isaacphysics.org/questions/maths_ch7_3_q7?board=b183ba68-9450-4e6d-a4b5-8f949afacb0a&stage=a_level) isaacphysics question: "Write down an expression for the rate of change of charge Q on the capacitor, in terms of Q and constants."

I had initially thought that Q=Q_0*e^(-t/(RC)), so differentiating this would give you an expression for dQ/dt=-Q_0/(RC)*e^(-t/(RC)), but this is wrong.

Original post by archieh0580

Having trouble solving this (https://isaacphysics.org/questions/maths_ch7_3_q7?board=b183ba68-9450-4e6d-a4b5-8f949afacb0a&stage=a_level) isaacphysics question: "Write down an expression for the rate of change of charge Q on the capacitor, in terms of Q and constants."
I had initially thought that Q=Q_0*e^(-t/(RC)), so differentiating this would give you an expression for dQ/dt=-Q_0/(RC)*e^(-t/(RC)), but this is wrong.

It looks like the question is asking about the charging phase and they want the right hand side in terms of Q (and other constants).

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