sin a+cos a=1/2

求证1+sina+cosa+2sinacosa/1+sina+cosa=sina+cosa求证1+sina+cosa+2sinacosa/1+sina+cosa=sina+cosa求证1+sina+c

求证:sin2a/1+sina+cosa=sina+cosa-1急求证:sin2a/1+sina+cosa=sina+cosa-1急求证:sin2a/1+sina+cosa=sina+cosa-1急s

证明Cos^A-Sin^A=1-2Sin^A=2Cos^A-1=cos^a-sin^a证明Cos^A-Sin^A=1-2Sin^A=2Cos^A-1=cos^a-sin^a证明Cos^A-Sin^A=

求证1+sina+cosa+2sina*cosa/1+sina+cosa=sina+cosa有什么思路!求证1+sina+cosa+2sina*cosa/1+sina+cosa=sina+cosa有什

sin2a+2sin方a/1+tana=2sinacosasin2a+2sin方a/1+tana=2sinacosasin2a+2sin方a/1+tana=2sinacosa证：sin2a=2sina

tana/2=sin/1+cosa=1-cosa/sinatana/2=sin/1+cosa=1-cosa/sinatana/2=sin/1+cosa=1-cosa/sinatana/2=sin(a/

求证：tana/2＝(1-cos)/sina=sina/(cosa+1)求证：tana/2＝(1-cos)/sina=sina/(cosa+1)求证：tana/2＝(1-cos)/sina=sina/

sina/(1+cosa)=1/2,求sina+cosasina/(1+cosa)=1/2,求sina+cosasina/(1+cosa)=1/2,求sina+cosasina/(1+cosa)=1/

已知sina-cosa=1/2,则sin^3a-cos^3a已知sina-cosa=1/2,则sin^3a-cos^3a已知sina-cosa=1/2,则sin^3a-cos^3a这种题目比较常见首先

证明sin^2A+sin^2B-sin^2A*sin^2B+cos^2A*cos^2证明sin^2A+sin^2B-sin^2A*sin^2B+cos^2A*cos^2B=1证明sin^2A+sin^

化简(1-sin^6a-cos^6a)/(cos^2a-cos^4a)==化简(1-sin^6a-cos^6a)/(cos^2a-cos^4a)==化简(1-sin^6a-cos^6a)/(cos^2

已知sina+cosa=-1/5求1）sinacosa2）sina-cosa已知sina+cosa=-1/5求1）sinacosa2）sina-cosa已知sina+cosa=-1/5求1）sinac

由cos(a+b)=cosacosb-sinasinbcos(a-b)=cosacosb+sinasinb解题设a为锐角,证：1、2分之根3乘cosa+2分之1乘sina=cos(6分之π-a)2、c

cosA+cos^2A=1,sin^2A+sin^4A+sin^8AcosA+cos^2A=1,sin^2A+sin^4A+sin^8AcosA+cos^2A=1,sin^2A+sin^4A+sin^

sin(a-b)*cosa-cos(a-b)*sina=1/5,则cos2b的值是sin(a-b)*cosa-cos(a-b)*sina=1/5,则cos2b的值是sin(a-b)*cosa-cos(

求证1/sin^2a+3/cos^2a>=4+2根号下31/sin²a+3/cos²a=(sin²a+cos²a)/sin²a+3(sin²

Sina+sin^2a=1,cos^2a+cos^s4a+cos^6aSina+sin^2a=1,cos^2a+cos^s4a+cos^6aSina+sin^2a=1,cos^2a+cos^s4a+c

证明tana/2=sina/(1+cosa)证明tana/2=sina/(1+cosa)证明tana/2=sina/(1+cosa)右边=2sin(a/2)cos(a/2)/(1+2cos(a/2)平

sin^4+sin^2cos^2+cos^2a=sin^4+sin^2cos^2+cos^2a=sin^4+sin^2cos^2+cos^2a=原式=sin²a(sin²a+cos

一个简单的三角函数题(sina+cosa)/(sina-cosa)则sina*cosa=(sina+cosa)/(sina-cosa)=2则sina*cosa=一个简单的三角函数题(sina+cosa