(6sin a+5cos a)/(5cos a+3sin a)=8,则tan a=__这道题能不能化成 6sin(a)+5cos(a)=40cos(a)+24sin(a)-35cos(a)=18sin(a)再将tan a比出来如果不行请大家为我讲讲,
问题描述:
(6sin a+5cos a)/(5cos a+3sin a)=8,则tan a=__
这道题能不能化成 6sin(a)+5cos(a)=40cos(a)+24sin(a)
-35cos(a)=18sin(a)
再将tan a比出来
如果不行请大家为我讲讲,
答
(6sin a+5cos a)/(5cos a+3sin a)
={(6sin a+5cos a)/sina}/{(5cos a+3sin a)/sina}
=[6+5ctga]/[5ctga+3]=8
得出ctga=-18/35
ctga=1/tga=-35/18