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
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![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](/uploads/image/z/4020602-50-2.jpg?t=%E5%B7%B2%E7%9F%A54sin%5E2+x+%E2%80%93+6sinx+%E2%80%93+cos%5E2+x+%2B+3cosx+%3D+0+%2C%E6%B1%82+cos%282x+%2B%CF%80%2F4%29+%2F+%5B%281-cos2x%29%28%E5%B7%B2%E7%9F%A54sin%5E2+x+%E2%80%93+6sinx+%3Dcos%5E2+x+-3cosx+%2C%E6%B1%82+cos%282x+%2B%CF%80%2F4%29+%2F+%281-cos2x%29%281-tan2x%29%E7%9A%84%E5%80%BC)
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