百科知识

已知函数y=4cos2x(sin2x

2019-06-02 18:28:50小***
已知函数y=4cos2x(sin2x-cos2x),求函数的值域需详细过程。已知函数y=4cos2x(sin2x,已知函数y=4cos2x(sin2x-cos2x),求函数的值域需详细过程。y=

最佳回答

  • y=4cos2x(sin2x-cos2x) =4cos2xsin2x-4(cos2x)^2 =2sin4x-2(1+cos4x) =2sin4x-2cos4x-2 =2(√2)sin(4x-π/4)-2 -2(√2)-2≤y≤2(√2)-2 值域[-2-2√2,-2+2√2]
    2019-06-02 19:02:09
  • 原式=4cos(2x)sin(2x)-4[cos(2x)]^2=2sin(4x)-2[cos(4x)+1] =2[sin(4x)-cos(4x)]-2 =2*根号2*sin(4x-pi/4)-2 值域是 [2*根号2-2 2*根号2+2]
    2019-06-02 18:56:56
  • y=4cos2x(sin2x-cos2x) =4sin2xcos2x-4(cos2x)^2 =2sin4x-2(1+cos4x) =2(sin4x-cos2x)-2 =2√2sin(4x-45°)-2, 其值域是[-2-2√2,2√2-2].
    2019-06-02 18:43:28
  • 很赞哦! (260)