化简:cos^2x(2cos^2x+3)-sin^2x(2cos^2x+3)-4sin^2xcos^2x+3
来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/10/05 22:58:16
化简:cos^2x(2cos^2x+3)-sin^2x(2cos^2x+3)-4sin^2xcos^2x+3
现将各项都乘开,然后将sin^2x=1-cos^2x带入
得8cos^4x
再问: 过程能不能大略写一下-
再答: cos^2x(2cos^2x+3)-sin^2x(2cos^2x+3)-4sin^2xcos^2x+3 =2cos^4x+3cos^2x-2cos^2xsin^2x-3sin^2x-4sin^2xcos^2x+3 =2cos^4x+3cos^2x-6cos^2xsin^2x-3sin^2x+3 =2cos^4x+3cos^2x-6cos^2x(1-cos^2x)-3(1-cos^2x)+3 =2cos^4x+3cos^2x-6cos^2x+6cos^4x-3+3cos^2x+3 =8cos^4x
得8cos^4x
再问: 过程能不能大略写一下-
再答: cos^2x(2cos^2x+3)-sin^2x(2cos^2x+3)-4sin^2xcos^2x+3 =2cos^4x+3cos^2x-2cos^2xsin^2x-3sin^2x-4sin^2xcos^2x+3 =2cos^4x+3cos^2x-6cos^2xsin^2x-3sin^2x+3 =2cos^4x+3cos^2x-6cos^2x(1-cos^2x)-3(1-cos^2x)+3 =2cos^4x+3cos^2x-6cos^2x+6cos^4x-3+3cos^2x+3 =8cos^4x
(1-(sin^4x-sin^2xcos^2x+cos^4x)/sin^2x +3sin^2x
sin^2x+cos^2x)(sin^4x-sin^2xcos^2x+cos^4x) =sin^4x-sin^2xcos
化简cos^4x+sin^2xcos^2x+sin^2x
化简[1-(sin^4x-sin^2cos^2x+cos^4x)/(sin^2)]+3sin^2x
化简y=sin^2(x)+2sin(x)cos(x)+3cos^2(x)
化简 1/2cos x-根号3/2sin x 根3sin x+cos x
证明sin^2(x)+cos^2(x+30)+sin(x)cos(x+30)=3/4
求导f(x) = cos(3x) * cos(2x) + sin(3x) * sin(2x).
化简(1)√3sin x+cos x (2)√2(sin x-cos x) (3)√2cos x-√6sin x
化简sin(3π-x)cos(x-3/2)cos(4π-x)/tan(x-5π)cos(π/2+x)sin(x-5/2π
化简 cos^2(x)*sin^2(x)-sin^2(x)
化简 cos^(2)(x)*sin^(2)(x)-sin^(2)(x)