(cos(3x+π/4)-sin(3x+π/4))/(cos(3x+π/4)+sin(3x+π/4))的值域 定义域 最小正周期

证明sin^2(x)+cos^2(x+30)+sin(x)cos(x+30)=3/4 化简[1-(sin^4x-sin^2cos^2x+cos^4x)/(sin^2)]+3sin^2x 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sin(3π-x)cos(x-3/2)cos(4π-x)/tan(x-5π)cos(π/2+x)sin(x-5/2π) 化简2sin^2[(π/4)+x]+根号3（sin^x-cos^x）-1 已知sin[a-b]cos a-cos[b-a]sin a=3/5,b是第三象限角,求sin[b+5π/4]的值第一题1/2cos x-√3/2sin x第二题√3sin x+cos x第三题√2[sin x-cos x]第四题√2cos x-√6sin x 2(sin^6x+cos^6)-3(sin^4x+cos^4x) 化简sin(x+7π/4)+cos(x-3π/4）步骤我已经找到撒sin(x+7π/4)+cos(x-3π/4)=sin(x+2π-π/4)+cos(x-π+π/4)我问下这一步是在干嘛?=sin(x-π/4)+cos[-(π-x-π/4)]=sin(x-π/4)+cos(π-x-π/4)=sin(x-π/4)-cos(x+π/4)=sin(x-π/4)-cos(x+π/2- (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 化简sin(x)(cos(x)+cos(3x)+cos(5x)+cos(7x)) cos (2x-π/3)=2sinπ/4 已知sin(x)+3cos(x)=2,求sin(x)-cos(x)/sin(x)+cos(x)=? f(x)=2sin^2(π/4+x)+根号3(sin^2x+cos^2x)f(x)=2sin^2(π/4+x)+根号3(sin^2x-cos^2x) 符号打错了 sin[cos^2(x^3+x)],求导 根号3sin x+cos x要化简 求证(3-sin^4 x-cos^4 x)/2cos^2 x=1+tan^2 x+sin^2 x 关于sin^2x+cos^2x 的应用式子：cos^6x+sin^6x=（cos^2x+sin^2x)(cos^4x-cos^2xsin^x+sin^4x)=(cos^2x+sin^2x)^2-3sin^2xcos^2x 求这两步算法中的具体思路 ps:cos^2x=cosx的二次方