Impedance between BJT base and ground of a common emitter amplifier circuit
I don't like to give full answers for homework questions but I always think a circuit diagram helps. The voltage at the emitter is 0.6V less than the base. The voltage across the emitter resistor can be calculated using ohms law (V/I). Now consider what the value of a resistor would be if Ib was to produce the same voltage as the emitter. (Ve / Ib). Does the 0.6V offset matter if you are looking for a change ? Is the value of Ie significantly different from Ic? You have all the relationships - do your homework.