sin(180+x)+cos(-x)/sin(180-x)+cos(360+x)=2 求tan(x+45)

问题描述:

sin(180+x)+cos(-x)/sin(180-x)+cos(360+x)=2 求tan(x+45)

sin(180+x)+cos(-x)/sin(180-x)+cos(360+x)
=[-sinx+cosx]/[sinx+cosx]
=2
-sinx+cosx=2sinx+2cosx
tanx=-1/3
tan(x+45)=(tanx+1)/(1-tanx)=[2/3]/(4/3)=1/2