(sin15°cos15°)/(cos^2 165°- sin^2 165°)

来源:学生作业帮助网 编辑:六六作业网 时间:2024/10/03 17:29:08
(sin15°cos15°)/(cos^2165°-sin^2165°)(sin15°cos15°)/(cos^2165°-sin^2165°)(sin15°cos15°)/(cos^2165°-si

(sin15°cos15°)/(cos^2 165°- sin^2 165°)
(sin15°cos15°)/(cos^2 165°- sin^2 165°)

(sin15°cos15°)/(cos^2 165°- sin^2 165°)
原式=(2sin15cos15)/[2(cos2*165)]
=sin30/2cos330
=sin30/2cos(360-30)
=sin30/2cos30
=1/2*tan30
=√3/6