解：(1)F????????i?t??t??f?t?edt???t0e?e?i?dt
?11?i?1??i?1??2f?t??1??2π???F???ei?td??1??1?i?2π???1??2ei?td??1??cos?t??sin?t2π???1??2dt ?1??cos?tπ???sin?t01??2dt(2) F?????????f?t?e?i?tdt
??0??e?i?t1?1?dt??0e?i?tdt?2?1?cos??i?f?t??1??2π???F???ei?td??1??2?1?cos??i?t2π???i?ed??1???1?cos??π???i??cos?t?isin?t?d??1???1?cos?? π?sin?t???d??2π????1?cos??sin?t0?d??t?0,1?40.求如图所示的三角形脉冲函数的频谱函数.
?E?2Et?T?t?解：f?t?????T20
?E?2Et0?t?T??T2F?????????f?t?e?i?tdt??02E?T?i?t2E??i??E?t?edt?2?T??2?0??E?Tt??e?tT?dt ?4E??TT?2??1?cos?2??
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