已知4sin^2 x – 6sinx – cos^2 x + 3cosx = 0 ,求 cos(2x +π/4) / [(1-cos2x)(已知4sin^2 x – 6sinx =cos^2 x -3cosx ,求 cos(2x +π/4) / (1-cos2x)(1-tan2x)的值

已知4sin^2 x – 6sinx – cos^2 x + 3cosx = 0 ,求 cos(2x +π/4) / [(1-cos2x)(已知4sin^2 x – 6sinx =cos^2 x -3cosx ,求 cos(2x +π/4) / (1-cos2x)(1-tan2x)的值
已知4sin^2 x – 6sinx – cos^2 x + 3cosx = 0 ,求 cos(2x +π/4) / [(1-cos2x)(
已知4sin^2 x – 6sinx =cos^2 x -3cosx ,求 cos(2x +π/4) / (1-cos2x)(1-tan2x)的值

已知4sin^2 x – 6sinx – cos^2 x + 3cosx = 0 ,求 cos(2x +π/4) / [(1-cos2x)(已知4sin^2 x – 6sinx =cos^2 x -3cosx ,求 cos(2x +π/4) / (1-cos2x)(1-tan2x)的值
四分之三根号二,待求的式子展开化简,等式配成完全平方就可以.可能会算错,但思路不会错