化简:sin{33° x}cos{27° x}
来源:学生作业帮助网 编辑:作业帮 时间:2024/08/07 10:20:29
sin(x+y)cos(x-y)+cos(x+y)sin(x-y)=sin(x+y+x-y)=sin2x再问:sin(x+y)cos(x-y)+cos(x+y)sin(x-y)为什么=sin(x+y+
sin(π-x)+sin(π+x)-cos(-x)+cos(2π-x)-tan(π+x)cot(π-x)=-sin(-x)-sin(x)-cos(x)+cos(-x)-[-tan(x)][-cot(-
据:cos2(x)=cosx^2-sinx^2=2cosx^2-1得:2sin^2(x)sin^2(φ)+2cos^2(x)cos^2(φ)-cos2(x)cos^2(φ)=2sin^2(x)sin^
根据公式sin(a-b)=sinacosb-cosasinb所以原式=sin(x+105-x+15)=sin120°=√3/2
[2cos³x-sin²(360°-x)+2sin(90°+x)+1]÷[2+2cos²(180°+x)+cos(-x)]=[2cos³x-sin²x
原式=cos[(x-25)-(65-x)]=cos(2x-90)=sin2x
这个方程无解取区间[-π,π]-1
cos(180°+x)*sin(x+360°)/[sin(-x-180°)*cos(-180°-x)]=-cosx×sinx/[-sin(180°+x)][cos(180°+x)]=-cosx×sin
=sin^2(x)*[cos^2(x)-1]=-sin^4(x)再答:别忘了负号再问:嗯谢谢
sin^4x-sin^2xcos^2x+cos^4x=sin^4x+2sin^2xcos^2x+cos^4x-3sin^2xcos^2x=(sin^2x+cos^2x)^2-3sin^2xcos^2x
3/2cosx-3/2(sinx)^2
原式=[sinx*(-cosx)*sinx]/[(-cosx)*sinx*(-sinx)]=-1
cos²(-X)-【tan(360°+X)】/【sin(-X)】=cos²X-tanX/-sinX=cos²X+1/cosX
[sin(180+x)-tan(-x)+tan(-360-x)]/[tan(x+180)+cos(-x)+cos(-x-180)]=[-sinx+tanx-tan(360+x)]/[tanx+cosx
y=sin²x+2sinxcosx+3cos²xy=(sin²x+cos²x)+2sinxcosx+(2cos²x-1)+1=1+sin2x+cos2
cos(33°-x)sin(63°-x)-cos(x+57°)sin(27°+x)=cos[90°-(x+57°)]sin[90°-(x+27°]-cos(x+57°)sin(x+27°)=sin(x
我来给你解答,稍等再答:
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(3x)+cos(5x)+cos(7x))
2(√3/2sinx+1/2cosx)=2sin(x+π/6)√2*√2(√2/2sinx-√2/2cosx)=2sin(x-π/4)(3)解;2√2(1/2cosx-√3/2sinx)=2√2cos