已知tanx=2求(2cos^2 x/2-sinx-1)/√ 2sin(x+π/4)
已知tanx=1/2,求sin x-cos x/2sinx+3cosx的值
已知(1+tanx)/(1-tanx)=3 求(sin^2x+2sinx·cosx-cos^2x)/(sin^2x+2c
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(1+tanx)/(1-tanx)=3+2√2,求(sin^2x+√2sinx*cosx-cos^2x)/(sin2
已知COS(π/4-X)=-4/5,求(SIN2X-2SIN^X)/(1+TANX)
已知tanx =根号3/3,求sinx+cos(派+x)/sinx+sin(派/2-x)的值
提问数学难题求证:sin^2x*tanx+cos^2x/tanx+2sinx*cosx=tanx+1/tanx
已知tanx=3,求4sin^2x+3sinx*cosx+6cos^x的值
1-2sinx cosx /COS^2X-SIN^2X =1-tanx/1+tanx 求证
已知cos(π/4+x)=3/5,求[sin2x-2(sinx)^2]/(1-tanx)
(1+tanx)/(1-tanx)=3+2根号2,求(sin x+cosx)^2-(cos^3x)/sinx
已知(1+tanx)/(1-tanx) =3+2根号2 ,求(sin^2 x+根号2sinx*cosx-cos^2 x)