x区进1时 (x-1)sin(1/x-1)与x-1比较 为什么两无穷小量无法比较

(sin 1/x) /x cos x/sin x+sin x/(1+cos x) 化简. lim (x^x-sin(x)^x)/(sin(x)sin(x)ln(1+tan(x))) x趋于零 化简(sin x+cos x-1)(sin x-cos x+1)/sin 2x sin(sinx)/x,x 趋于0的极限sin(sin(x))/x=[sin(sin(x))/sin(x)]*sin(x)/x=1*1=1sin(sin(x))/sin(x)这一部我不明白阿 x*（1+sin^2 x )/sin^2x 不定积分 为什么当x→0时极限sin(x*sin(1/x))/x*sin(1/x)不存在 傅里叶级数作图f（x）=2sin[x] - sin[2x] + 2/3sin[3x] - 1/2sin[4x]我用mathematica输入程序Plot[{2sin[x],-2sin[x],2sin[x] - sin[2x],-2sin[x] + sin[2x],2sin[x] - sin[2x] + 2/3sin[3x],-2sin[x] + sin[2x] - 2/3sin[3x],2sin[x] - sin[2x] + 2/3si 化简(sin^2 x/sin x-cosx)-(sin x+cosx/tan^2 x-1) (1-(sin^4x-sin^2xcos^2x+cos^4x)/sin^2x +3sin^2x 化简[1-(sin^4 x-sin^2 xcos^2 x+cos^4 x)]/(sin^2 x)+3sin^2 x x-1/sin(x-1)导数 1/(sin x+cos x) 的不定积分 (1+cos x-sin x)/(1-sin x-cos x)+(1-cos x-sin x)/(1-sin x+cos x)=? (1+tan(x))/sin(2x)不定积分 ∫ x sin(x+1) dx cos x/( 1-sin x)化简 ((sin x) -1)^2 对x求导