cos^X+sin^2(X-180\'/3)-cos(X+180\'/3)cosX

f(x)=2(cosx)^3+sin(360°-x)^2-cos(180°-x)-3/2+2cos(180°+x)+cos(-x)求f(π/3)f(x)=2(cosx)^3+(sinx)^2+cosx-3/2-2cosx+cosx=2(co

sinx+cosx/sinx-cosx=2求sinx/cos^3x+cosx/sin^3x由(sinx+cosx)^2=1/25得2sinxcosx＝－24/25,(sinx-cosx)^2=48/25得sinx-cosx=-4√3/5,故

证明成立：[cos(3x)-sin(3x)]/(cosx+sinx)=1-2sin(2x).cos(3x)-sin(3x)=cos(2x+x)-sin(2x+x)=cos2xcosx-sin2xsinx-sin2xcosx-cos2xsin

已知2sin平方x-3sinxcosx+cos平方=0求(cosx-sinx)/(cosx+sinx)2sin²x-3sinxcosx+cos²x=0所以（2sinx-cosx）（sinx-cosx）=0所以2sinx=

已知sinx+cosx/sinx-cosx=2,求2cos(π-x)-3sin(π+x)/4cos(-x)+sin(2π-x)是(sinx+cosx)/(sinx-cosx)=2和[2cos(π-x)-3sin(π+x)]/[4cos(-x

(sinx*sin3x)sin^2x+（cosx*cos3x)cos^2x如何变到1/2[(cos2x-cos4x)sin^2x+(cos2x+cos4x)cos^2x]sinx*sin3x=(1/2)[cos(x-3x)-cos(x+3x

已知sin(x)+3cos(x)=2,求sin(x)-cos(x)/sin(x)+cos(x)=?sinx+3cosx=2,①(sinx)^2+(cosx)^2=1.②由①,sinx=2-3cosx,③代入②,10（cosx)^2-12co

(cos(x/2)/(根号1+sinx))+(sin(x/2)/根号(1-cosx)),x属于(3/2π,2π)∵sin(x/2)=±√[(1-cosx)/2]cos(x/2)=±√[(1+cosx)/2又∵x∈（3π/2,2π）∴3π/4

(sin^2x-2sinx*cosx-cos^2x)/(4cos^2x-3sin2x）,已知tanx=2,求值(sin^2x-2sinx*cosx-cos^2x)/(4cos^2x-3sin2x)=(sin^2x-2sinx*cosx-co

已知4sin^2x–6sinx–cos^2x+3cosx=0,求cos(2x+π/4)/[(1-cos2x)(已知4sin^2x–6sinx=cos^2x-3cosx,求cos(2x+π/4)/(1-cos2x)(1-tan2x)的值四分之

2sin*x-cos*x+sinxcosx-6sinx+3cosx=0,求2cos*x+sin2x除以1+tanx的值这是一道高一的三角题,个人认为有点难,请大家帮助2(sinx)^2-(cosx)^2+sinxcosx-6sinx+3co

sin[cos^2(x^3+x)],求导=cos[cos^2(x^3+x)]×[cos^2(x^3+x)]'=cos[cos^2(x^3+x)]×2cos(x^3+x)[cos(x^3+x)]'=-cos[cos^2(x^3+x)]×2co

sin(180+x)+cos(-x)/sin(180-x)+cos(360+x)=2求tan(x+45）sin(180+x)+cos(-x)/sin(180-x)+cos(360+x)=[-sinx+cosx]/[sinx+cosx]=2-

2sin^2x-5sinxcosx=3cos^2x,求X,因式分解一下得到（sinx-3cosx)(2sinx+cosx)=0所以得到sinx-3cosx=0或2sinx+cosx=0所以tanx=3或-1/2所以x=actan3或acta

化简sin(x)(cos(x)+cos(3x)+cos(5x)+cos(7x))利用积化和差公式sinAcosB=(1/2)*[sin(A+B)+sin(A-B)]以及sin(-A)=-sinA的性质可得sin(x)(cos(x)+cos(

sinx-1)/cosx怎么化成[sin(x/2)-cos(x/2)]/[cos(x/2)+sin(x/2(sinx-1)/cosx=(2sinx/2cosx/2-sin^2x/2-cos^2x/2)/(cos^2x/2-sin^2x/2)

cos^2xcos2xcosx^2cos^3x求导数要求给出sin和前面公式一样的=（cos^2x）'cos2xcosx^2cos^3x+cos^2x(cos2x)'cosx^2cos^3x+cos^2xcos2x(cosx^2)'cos^

sinx+cisx=a,则sinxcosx=?sin^3x+cos^3x=?sin^4x+cos^4x?1、因为,(sinx+cosx)²=a²所以,sinxcosx=(a²-1)/22、sin^3x+cos^

若sinX+cosX=根号2,求sin^3X+cos^3X的值sin^3X+cos^3X=（sinx+cosx)(sin^2x-sinxcosx+cos^2x)=根号2(1+sinxcosx)sinX+cosX=根号2所以sin^2x+co

sinX-cosX=1/2,则sin^3X-cos^3X=?RT∵sinX-cosX=1/2（sinX-cosX）^2=sin^2X-2sinXcosX+cos^2X=1-2sinXcosX=1/4∴sinXcosX=3/8∴sin^3X-