已知函数f(x)=1 2sin2x-根号3cos^2x
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a=(√3sinx/2,cosx/2),b=(cosx/2,-cosx/2)f(x)=a·b=√3sin(x/2)cos(x/2)-(cosx/2)^2=(√3/2)sinx-(1/2)cosx-1/
f(sin(x/2))=cosx+1=1-2(sin(x/2))^2+1=2-2(sin(x/2))^2令y=sin(x/2)则f(y)=2-2y^2令y=cos(x/2)f(cos(x/2))=2-
分析:先利用二倍角公式和两角和公式对函数解析式进行化简,得到一个角的一个三角函数的形式,然后再求出函数h(x)的解析式,再根据正弦函数的对称性和t的范围求出t的值.∵y=【2sin²(x+π
(Ⅰ)∵f(x)=sin2ωx+3cosωx•cos(π2−ωx)−12=1−cos2ωx2+32sin2ωx−12 =32sin2ωx−12cos2ωx=sin(2ωx−π6).(2分)&
f(x)=sin2(x+π)+根号3sin(x+π)sin(π-x)-1\2=sin2x-根号3sin²x-1/2=sin2x+根号3/2cos2x-1=根号7/2sin(2x+γ)-1co
(1)由题意得,f(x)=(sinxcosπ6−cosxsinπ6)2+(cosxcosπ3+sinxsinπ3)2+sinx•cosx=sin2x+sinx•cosx+12=12(sin2x−cos
(Ⅰ)∵f(x)=3sin(2x-π6)+1-cos(2x-π6)=1+2sin(2x-π3),∵ω=2,∴函数f(x)的最小正周期为π;(Ⅱ)∵x∈[-π4,π4],∴2x-π3∈[-5π6,π6]
f(x)=sinxsin(xπ/2)=sinxcosx故f(x)的最小正周期是2πf^2(x)=(sinxcosx)^2=1sin2xsin2x=-7/16sin(xπ/2)=cosxf
f(x)=sin2(2x-π4)=1−cos(4x−π2)2根据三角函数的性质知T=2π4=π2故答案为:π2
f(x)=sinx+sin[x+(π/2)=sinx+cosxf(α)=sinα+cosα=3/4因为sin2α=2sinαcosα所以sin2α=2sinαcosα=(sinα+cosα)^2-[(
(1)由题意得,f(x)=(sinxcosπ6−cosxsinπ6)2+(cosxcosπ3+sinxsinπ3)2+sinx•cosx=sin2x+sinx•cosx+12=12(sin2x−cos
(1)∵sin2(x-π12)=12[1-cos2(x-π12)]=12-12cos(2x-π6)∴f(x)=3sin(2x-π6)+[1-cos(2x-π6)]=2[sin(2x-π6)cosπ6-
(Ⅰ)f(x)=1−cos(x+π6)2+32sin(x+π6)−12=32sin(x+π6)−12cos(x+π6)=sinx所以f(x)的值域为[-1,1](Ⅱ)由正弦曲线的对称性、周期性可知x1
f(x)=(sinωx-cosωx)2+2sin2ωx=1-2sinωxcosωx+(1-cos2ωx)=2-sin2ωx-cos2ωx=2-2sin(2ωx+π4)由T=2π3,得到|ω|=32,又
f'(x)=πeπx•sin2πx+2πeπx•cos2πx=πeπx(sin2πx+2cos2πx),则f′(12)=πeπ2(sinπ+2cosπ)=−2πeπ2.
(1)f(x)=3sin(2x-π6)+1-cos(2x-π6)=2[32sin(2x-π6)-12cos(2x-π6)]+1=2sin(2x-π3)+1,∵ω=2,∴T=π;(2)令2x-π3=2k
(I)∵f(x)=2sin2(π4+x)-3cos2x=1-cos(π2+2x)-3cos2x=1+sin2x-3cos2x=2sin(2x-π3)+1.(1分)∴周期T=π;(1分)令2kπ-π2≤
f(x)=sin2/xcos2/x-sin^22/x=1/2sin4/x+1/2cos4/x-1/2=√2/2sin(4/x+π/4)-1/2则当(4/x+π/4)∈(2kπ-π/2,2kπ+π/2)