5cos(x-y/2)+7cos(y/2)=0求tan(x/2)*tan[(x-y)/2]
已知2cos(2x+y)=cosy,求tan(x+y)tany的值
cos(2x+y)=3cosy,求tanx*tan(x+y)
1.已知8cos(2x+y)+5cosy=0,求tan(x+y)*tanx的值.
tan(x+y)tan(x-y)=sin^2x-sin^2y/cos^2x-sin^2y 顺便问一下. tan,sin,
已知3cos(2x+y)+5cosy=0,则tan(x+y)tanx的值是
请问怎么证明sinX+sin(X+Y)+sin(X+2Y)/cosX+cos(X+Y)+cos(X+2Y)=tan(X+
y′=y/x+tan[(y/x)^2]
已知tan=2,求(cos x+sin x)/(cos x-sin x)+sin^2x
sin(x+y)sin(x-y)=k,求cos^2x-cos^2y
求y=|cosx| y=|tanx| y=sin|x| y=cos|x| y=tan|x|周期
已知tanx=-1/3,cosy=根号5/5,求tan(x+y)的值和函数f(x)=根号2sin(a-x)+cos(a+
y =(cos^2) x - sin (3^x),求y'