f(x)=(6sin^4x-7sin^2x+2)/(sin^2x-cos^2x)

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/03 17:23:47
f(x)=(6sin^4x-7sin^2x+2)/(sin^2x-cos^2x)

f(x)=(6sin^4x-7sin^2x+2)/(sin^2x-cos^2x)
f(x)=(6sin^4x-7sin^2x+2)/(sin^2x-cos^2x)

f(x)=(6sin^4x-7sin^2x+2)/(sin^2x-cos^2x)
化简:f(x)=(6sin⁴x-7sin²x+2)/(sin²x-cos²x)
f(x)=(2sin²x-1)(3sin²x-2)/(sin²x-cos²x)=[sin²x-(1-sin²x)](3sin²x-2)/(sin²x-cos²x)
=(sin²x-cos²x)(3sin²x-2)/(sin²x-cos²x)=3sin²x-2

(-1 - 3 Cos2x)/2

f(x)=(6sin^4x-7sin^2x+2)/(sin^2x-cos^2x)
=(2sin^2x-1)(3sin^2-2)/[sin^2x-(1-sin^2x)]
=3sin^2x-2
=3[(2sin^2x-1)+1]/2
=3(-cos2x+1)/2
=3(1-cos2x)/2