Differentiator circuit - can output be larger than input?
Your formula is only true for an active differentiator, which includes (most simply) an op-amp (figure below). In this situation, there's a power supply, which sets the maximum output voltage, which can be higher than the input voltage. The properties of the op-amp will determine what happens if your formula predicts higher output voltages, but most likely it will saturate.



For the circuit that is only a capacitor and resistor, it's more properly thought of as a high-pass filter. There is a response something like a derivative, but it's not as simple. You can find more on wikipedia at https://en.wikipedia.org/wiki/Differentiator