(cos^2 2x-sin^2 2x)/(1-tan2x)=(1+2sin2xcos2x)/(1+tan2x)
来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/06/08 22:14:35
(cos^2 2x-sin^2 2x)/(1-tan2x)=(1+2sin2xcos2x)/(1+tan2x)
(1+2sin2xcos2x)/(cos²2x-sin²2x)
= (sin²2x+cos²2x+2sin2xcos2x)/(cos²2x-sin²2x)
= (sin2x+cos2x)²/[(cos2x+sin2x)(cos2x-sin2x)]
= (sin2x+cos2x)/(cos2x-sin2x)
= (1+tan2x)/(1-tan2x)【分子分母同除cos2x】
移项得:(cos^2 2x-sin^2 2x)/(1-tan2x)=(1+2sin2xcos2x)/(1+tan2x)
= (sin²2x+cos²2x+2sin2xcos2x)/(cos²2x-sin²2x)
= (sin2x+cos2x)²/[(cos2x+sin2x)(cos2x-sin2x)]
= (sin2x+cos2x)/(cos2x-sin2x)
= (1+tan2x)/(1-tan2x)【分子分母同除cos2x】
移项得:(cos^2 2x-sin^2 2x)/(1-tan2x)=(1+2sin2xcos2x)/(1+tan2x)
(cos^2 2x-sin^2 2x)/(1-tan2x)=(1+2sin2xcos2x)/(1+tan2x)
求证(tanxtan2x/tan2x-tanx)/(tan2x-tanx)+√3(sin^2x-cos^2x)=2sin
已知sin^2x+sin2x*sinx+cos2x=1,x属于(0,派/2),求tan2x
已知tan2x=-2 π/2<2x<π求[2cos^2(x/2)-sinx-1]/根号2sin(π/4+x)
设n>=2,当x不等于k派,求证:tanx*tan2x+tan2x*tan3x+.+tan(n-1)*tannx=tan
lim(x→0)ln tan7x/ln tan2x= lim(x->0) [7(tan2x)·cos²2x]/
求证tanx-1/tanx=-2/tan2x
已知x属于(0,2/π),tanx=2/1,tan2x和sin(2x+3/π)的值
设tan2x=2*根号2 ,x属于(π/2,π),求【2cos(x/2)^2 - sinx-1 】/【sinx+ cos
极限x趋向0 tan2x/(1+x+x^2)^1/2-1 是多少?
已知函数f(x)=tanxtan2x/tan2x-tanx+根号3(sin^2x-cos^2x)求函数f(x)的定义域和
设y=(tan2x)^cot(x/2) ,求dy/dx