化简3 2cosx-√3 2sinx
来源:学生作业帮助网 编辑:作业帮 时间:2024/09/27 12:07:18
y=2(1-2sin²x)+sin²x-4cosx=2-3sin²x-4cosx=2+3cos²-3-4cosx=3cos²-4cosx-1;再问:-
1.f(x)=2cosx*sin(x+π/3)-√3sin^2x+sinx*cosx=2cosx*sin(x+π/3)-2sinx*[(√3/2)sinx-(1/2)cosx]=2cosx*sin(x
(sin(cosx^2))'=cos(cosx^2)*(cosx^2)'=cos(cosx^2)*(-sinx^2)*2x=-[2xcos(cosx^2)*sinx^2]
sin(x+y)sinx+cos(x+y)cosx=(sinxcosy+sinycosx)sinx+(cosxcosy-sinxsiny)cosx=(sinx)^2*cosy+(cosx)^2*cos
sin(x+y)sinx+cos(x+y)cosx=cosy这是公式!
tan²-1=sin²x/cos²x-1=(sin²x-cos²x)/cos²x=(sinx+cosx)(sinx-cosx)/cos&su
[sin^2(x)]/(sinx-cosx)-(sinx+cosx)/[tan^2(x)-1]-sinx=sin^2x/(sinx-cosx)-(sinx+cosx)/[(tanx+1)(tanx-1
[1+2cosx/2*sinx/2+cos(x/2)^2-sin(x/2)^2][sin(x/2)-cos(x/2)]/根号下的[2*2cos(x/2)^2]=2cos(x/2)[sin(x/2)+c
sinx+cosx=√2(cos45°sinx+sin45°cosx)=√2sin(x+45°)==√2sin(x+π/4)
1、[-π/2+2Kπ,π/2+2Kπ]2、1/83、-1/2arcsin(√10/20)
原式通分=[(sinx-cosx)²+(sinx+cosx)²]/(cosx+sinx)(cosx-sinx)=2(sin²x+cos²x)/(cos²
sin(cosx)≥0∴2kπ≤cosx≤(2k+1)π(注:[2kπ,(2k+1)π]=……∪[-4π,-3π]∪[-2π,-π]∪[0,π]∪[2π,3π]∪……)又∵-1≤cosx≤1∴0≤co
sin⁴x/(sinx-cosx)-(sinx+cosx)cos²x/(tan²x-1)=sin⁴x/(sinx-cosx)-(sinx+cosx)cos&
cos(X-Y)=cosXcosY+sinXsinY原式=cos(30.)再问:能写具体点吗?谢谢了再答:原式=cos(X+30。-X)=cos(30。),按着给的那个公式看就对了
sin(x-π/3)-cos(x+π/6)+√3cosx=sinxcosπ/3-cosxsinπ/3-cosxcosπ/6+sinxsinπ/6+√3cosx=1/2*sinx-√3/2*cosx-√
中括号提(sinx)平方,前面小括号展开即得结果:sinx再问:麻烦详细点,后面的那个分式怎么化简?
(sinx)^4+(cosx)^4=[(sinx)^2+(cosx)^2]^2-2(sinx)^2(cosx)^2=23/321^2-2(sinxcosx)^2=23/32(sinxcosx)^2=9
通分,分母=sin^2`x(tan^2`x-1)-(sinx+cosx)(sinx-cosx)=(sin^2-cos^2)^2/cos^2 中间步骤略 分子=(sin^2-cos^2)(sin-c
cos(x+y)sinx-sin(x+y)cosx=sin[x-(x+y)]=sin(-y)=-siny