butterworth low pass filter

[vead]

butterworth digital low pass filter has following specification

passband-0-500 hz
stopband-2-4 khz
passband ripple-3 db
stopband attenuation-20 db
sampling frequency-8 khz

determine the passband and stopband edge frequency


please tell me the hint or formula to calculate passband and stopband frequency

 

[godfreyl]

To start with, those specs don't describe a Butterworth filter.
Sounds more like a Chebyshev filter or an elliptic filter.

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