求职cos40度*(1+根号3tan10度)要过程谢谢
问题描述:
求职cos40度*(1+根号3tan10度)要过程谢谢
答
cos40(1+√3tan10)
=cos40(cos10+√3sin10)/cos10
=cos40(2sin(10+30)/cos10
=2cos40sin40/cos10
=sin80/cos10
=cos10/cos10
=1
答
cos40度*(1+根号3tan10度)
=(cos30cos10-sin30sin10)(1+根号3tan10度)
=(cos30cos10-sin30cos10)(cos10+根号3sing10度)/cos10=1