Z
zhingeng


1/cos 10x-cos 8x-cos 6x+1=0
2/8cos^4(x+pi/4)+sin4x=2.\frac{1-tan^2 x}{1+tan^2x}
3/1-2căn3.sin x+3sin^2 x=cos^2 2x
4/8cos x+6sin x-cos 2x-7=0
5/sin(3pi/5+2x)=2sin^2(pi/5-x)
6/1+sinx+cosx+sin2x+cos2x=0
2/8cos^4(x+pi/4)+sin4x=2.\frac{1-tan^2 x}{1+tan^2x}
3/1-2căn3.sin x+3sin^2 x=cos^2 2x
4/8cos x+6sin x-cos 2x-7=0
5/sin(3pi/5+2x)=2sin^2(pi/5-x)
6/1+sinx+cosx+sin2x+cos2x=0