f(x)=sin(wx y) cos(wx y)的周期为π,f(-x)=f(x)
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f(x)=2(cosx)^3+(sinx)^2+cosx-3/2-2cosx+cosx=2(cosx)^3+1-(cosx)^2-3/2=2(cosx)^3-(cosx)^2-1/2f(π/3)=2(
积分值=(变量替换x=pi/2-t)积分(0到pi/2)f(cosx)/(f(sinx)+f(cosx)),两者相加(就是两倍的积分值),被积函数是1,故积分值是pi/2,因此原积分值是pi/4
(x*cosx-sinx)/x^2
(Ⅰ)∵向量a=(cos2ωx-sin2ωx,sinωx),b=(3,2cosωx),∴f(x)=a•b=(cos2ωx-sin2ωx,sinωx)•(3,2cosωx)=3cos2ωx+sin2ωx
2kπ+5π/6=(2k+1)π-π/6他和2kπ-π/6区别是π的系数一个是奇数,一个是偶数所以可以合起来,就是整数同样2kπ+7π/6=(2k+1)π+π/6和2kπ+π/6也合并成整数而整数就可
a=(1,-2sinx)b=(cos2x,cosx)f(x)=cos2x-2sinxcosx+a=cos2x-sin2x+a=√2cos(2x+π/4)+a(1).T=2π/2=π(2)0≤X≤π/2
设x0所以f(-x)=sin2(-x)+cos(-x)=-sin2x+cosx因为f(x)为奇函数,所以f(-x)=-f(x)得f(x)=-f(-x)=sin2x-cosx(x
f(1)+f(2)+f(3)+f(4)+f(5)+f(6)+f(7)+f(8)=(1/根号2)+1+(1/根号2)+0+(-1/根号2)+(-1)+(-1/根号2)+0=0以8为循坏的加法2010=2
(1)f(x)=2sinx(32cosx-12sinx)+3sinxcosx+cos2x=23sinxcosx+cos2x-sin2x=3sin2x+cos2x=2sin(2x+π6)…(6分)∴f(
f(x)=sin(π-x)cos(3π/2+x)+sin(π+x)sin(3π/2-x)=(sinx)(sinx)+(-sinx)(-cosx)=sinx(sinx+cosx)f'(x)=cosx(s
f(x)=cos(3x)*cos(2x)+sin(3x)*sin(2x)=cos(3x-2x)=cosxf'(x)=-sinx
(根号2+根号6)÷4再问:如何做的??????????谢谢
(1)sin(A+π/4)=√2/2sinA+√2/2cosA=(7√2)/10sinA+cosA=7/5sinA=7/5-cosA^2sinA^2+cosA^2=1(7/5-cosA)^2+cosA
∵f(cosx)=sin3x∴f(sinx)=f[cos(π/2-x)]=sin[3(π/2-x)]=sin(3π/2-3x)=-cos3x选D再问:呃,不太明白怎么变的。。。。。。再答:f()括号内
cosx=1-2(sinx/2)^2f=[sin(2/x)]=1+cosx=2-2(sinx/2)^2f(x)=2-2x^2f[cos(2/x)]=2-2[cos(2/x)]^2
cos(sin(x))cos(x)
2-x2再问:写下过程吧??!!
(Ⅰ) 因为f(x)=32sin2ωx-12(1+cos2ωx)=sin(2ωx-π6)-12,所以 T=2π2ω=π2,∴,ω=2.(Ⅱ) 因为x是△ABC的最小内角,
f(x)=[cos(x)+sin(x)]sin(x)=cos(x)sin(x)+sin^2(x)=1/2sin2x+1/2(1-cos2x)=√2/2[cos(p/4)sin2x-sin(p/4)co
f(sinx-1)=cos2x+2cos2x=1-2sin^2xf(sinx-1)=3-2sin^2x=-2(sinx-3/4)^2+7.5f(x)=-2(x+1/4)^2+7.5