Cecil Moore wrote:
Given any two superposed coherent voltages, V1 and
V2, with a phase angle, A, between them:

If ( 0 = A 90 ) then there exists constructive
interference between V1 and V2, i.e. cos(A) is a
positive value.

i.e. (V1^2 + V2^2) (V1 + V2)^2

If A = 90 deg, then cos(A) = 0, and there is no
destructive/constructive interference between
V1 and V2.

i.e. (V1^2 + V2^2) = (V1 + V2)^2

If (90 A = 180) then there exists destructive
interference between V1 and V2, i.e. cos(A) is a
negative value.

i.e. (V1^2 + V2^2) (V1 + V2)^2
--
73, Cecil http://www.w5dxp.com