Someone can Explain this digital filter design, I don't know how to apply the properties of the windows on this.

4. An analog signal xe(t) = 5cos(400?) + 10sin(500mt) is to be processed by a digital signal processing (DSP) system in which the sampling frequency is 1 kHz. Suppose that we want to pass the first component of r(t) with attenuation of less than 1 dB, but attenuate the second component to at least 50 dB. Sketch the specification of the digital filter in such a DSP system, and identify the cutoff frequency We and transition bandwidth ?? of the desired digital filter. 4. An analog signal xe(t) = 5cos(400?) + 10sin(500mt) is to be processed by a digital signal processing (DSP) system in which the sampling frequency is 1 kHz. Suppose that we want to pass the first component of r(t) with attenuation of less than 1 dB, but attenuate the second component to at least 50 dB. Sketch the specification of the digital filter in such a DSP system, and identify the cutoff frequency We and transition bandwidth ?? of the desired digital filter