Find the Laplace transforms of the following waveforms and plot their pole-zero diagrams. (a) f 1 t

Find the Laplace transforms of the following waveforms and plot their pole-zero diagrams.

(a) f 1

ðtÞ ¼ 2dðtÞ þ 200e200t þ 400e400t

 

uðtÞ

(b) f 2

ðtÞ ¼ 15e200t þ 15 cos 500t

 

uðtÞ