已知tan2x=-2 π/2<2x<π求[2cos^2(x/2)-sinx-1]/根号2sin(π/4+x)
已知tan2x=-2 π/2<2x<π求[2cos^2(x/2)-sinx-1]/根号2sin(π/4+x)
已知0<A<π/2<B<π,cos(B-π/4)=1/3,sin(A+B)=4/5求cos(a+
设tan2x=2*根号2 ,x属于(π/2,π),求【2cos(x/2)^2 - sinx-1 】/【sinx+ cos
已知sin^2x+sin2x*sinx+cos2x=1,x属于(0,派/2),求tan2x
(1)已知sinx+cosx=根号2/2,求sin^4x+cos^4x
已知sin[(π/4)-x)]=5/13,0<x<π/4.求cos2x/(cosπ/4+
已知sin(x/2)-2cos(x/2)=0,求tanx的值,求cos2x除以根号2*cos(π/4+x)*sinx的值
已知COS(x-π/4)=根号2/10,x属于(π/2,3π/4).(1)求sinx的值.(2)求sin(2x+π/3)
已知tan(a+π/4)=-1/2,π/2<a<π,求(sin2a-2cos^2a)/√2sin(a-π/4
(已知0<α<π,tanα=-2) 求2sin²α-sinαcosα+cos²α 求老师
已知π/4<a<b<π/2,且sin(a+b)=4/5,cos(a-b)=12/13
已知函数f(x)=tanxtan2x/tan2x-tanx+根号3(sin^2x-cos^2x)求函数f(x)的定义域和