Signals and Systems - Section 1 (6)

A linear system is one in which the relationship between input and output is linear.

All linear system possess the property of superposition i.e., if input u₁ gives output y₁ and input u₂ gives output y₂ then input u₁ + u₂ will give output y₁ + y₂.

Superposition implies homogencity i.e., if input u gives output y, then input ku gives output ky where k is a rational number.

In general a system is linear if a transformation T satisfies the relation

T(au₁ + βu₂) = aT(u₁) + βT(u₂)

where a and β are constant.

Because to design band pass or band stop, transfer function of must be second order.

DC meter reads mean value.

Add elements individually.

For third harmonic θ = tan^-1 

But still we will get the same response, zero are at same position.