图示正弦电流电路中电压u()的初相等于( )。
·36.9°
·- 36.9°
·- 53.1°
·53.10<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1633761511391f01718a015d24cf4a4604f4d6559a310image12.png"
出自:西南石油大学土木工程施工与组织(专升本)