0 votes 0 votes Which of the following cannot be the Fourier series expansion of a periodic signal ? $x(t)=2 \cos t+3 \cos 3 t$ $x(t)=2 \cos \pi t+7 \cos t$ $x(t)=\cos t+0.5$ $x(t)=2 \cos 1.5 \pi t+\sin 3.5 \pi t$ Others gate2002-ec + – admin asked Sep 27, 2022 • edited Nov 30, 2023 by makhdoom ghaya admin 46.4k points 62 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.