若<img src="https://static.zxtiku.com/wangke/imgs/topic/4b1754bec7cd49b47278297d63ac1983.jpg"/>，<img src="https://static.zxtiku.com/wangke/imgs/topic/2dc69cc25678651d1131214e436824c5.jpg"/>，则<img src="https://static.zxtiku.com/wangke/imgs/topic/c16f17fa78fcddda44d6de94d64b18e6.jpg"/>与<img src="https://static.zxtiku.com/wangke/imgs/topic/da54c9b6c46d1e3181b679b6a604ec21.jpg"/>的相位差<img src="https://static.zxtiku.com/wangke/imgs/topic/5b090ffc98f99b69cc1a8b39dfcf21b2.jpg"/>为：