The medium between the two communicating systems can transmit frequencies from $1MHz$ to $42,5MHz.$

The signal used in data transmission in this system is defined as follows:

$S(t)=1,27$Sin$(2ft)+3,82$Sin$(6ft)+6,37$Sin$(10ft)+8,91$Sin$(14ft)+$

$11,46$Sin$(18ft)+14,01$Sin$(22ft)+16,55$Sin$(26ft)+19,10$Sin$(30ft)+21,65$Sin$(34ft)$

According to this information;

a$.$ If $"f"$ frequency is selected as $8MHz,$ define spectrum, absolute bandwidth, effective bandwidth and

harmonics of signal?

b$.$ To achieve highest bandwidth and use all harmonics, select $"$ f $"$ frequency. According to this selection

define spectrum, absolute bandwidth, and effective bandwidth of signal?