已知函数y=sin(3 pai-2x

y=sin(1/2x+π/3)函数y的最大值是1,此时1/2x+π/3=2kπ+π/2,k∈Z.X=4kπ+π/3,k∈Z.x的集合为{x|X=4kπ+π/3,k∈Z}2kπ+π/2≤1/2x+π/3

(1)因为x∈[π/4,π/2]所以2x-π/3∈[π/6,2π/3]所以x=5π/12时有最大值3,x=π/4时有最小值2（2）若不等式-2

是2π/（π/6）=12再问：前面的1/2不往里乘么再答：不用

最大值为1,当2x-π/3=π/2+2kπ时,x=5π/12+kπ,k属于整数最小值为-1,当2x-π/3=3π/2+2kπ时,x=11π/12+kπ,k属于整数

fx=2sin(2x+pai/6)振幅A=2最小正周期T=2pai/2=paix∈【0,pai/]2xE[0,2pai]2x+pai/6E[pai/6,2pai+pai/6]很明显,设u=2x+pai

晕我不能发图啦给你个链接自己看http://photo.blog.sina.com.cn/photo/3f05ad5eg84fe6cb14ce9

y=f(x)=(sinx)平方-根号3sin(pai+x)*cosx=(1/2)(1-cos2x)+根号3sinxcosx=(√3/2)sin2x-(1/2)cos2x+1/2=sin(2x-π/6)

π/2≤x+π/3≤4π/3=>[π/2,4π/3]⊑[π/2,3π/2]函数y=sin(x+pai/3)的一个单调减区间是[pai/6,pai]是对的

1.y=3sin(2x+π/3)=3sin[2(x+π/6)],2(x+π/6)=π/2=>x=π/12=>对称轴x=kπ+π/12,或x=kπ+7π/122.y=sinx的图像,振幅扩大为原来的3倍

y=sin(π/2+x)*cos(π/6-x)=cosx*(cosπ/6*cosx+sinπ/6*sinx)=√3/2(cosx)^2+1/2sinx*cosx=√3/4cos2x+√3/4+1/4s

f(x)=cos(2x-π/3)+2sin(x-π/4)cos[π/2-(x+π/4)]=cos(2x-π/3)+2sin(x-π/4)cos(π/4-x)=cos(2x-π/3)+2sin(x-π/

y=1/2sin(2x+π/3)-sinxcosx=1/2(1/2sin2x+√3/2cos2x)-1/2sin2x=1/2(-1/2sin2x+√3/2cos2x)=1/2(cosπ/6cos2x-

解由y=sin（pai/4-2x）=-sin(2x-π/4)知当2kπ-π/2≤2x-π/4≤2kπ+π/2,k属于Z时,y是减函数.即当kπ-π/8≤x≤kπ+3π/8,k属于Z时,y是减函数.故函

y=sin(x+π/3)sin(x+π/2)=sin(x+π/3)cosx=(sinxcosπ/3+cosxsinπ/3)cosx=1/2sinxcosx+√3/2cos^2(x)[cos^2(x)指

周期4派,振幅3,初相负四分之派,对称轴4派加减1.5派单调递增2K派减0.5派到2K派加1.5派之间

2x+π/3=(kπ+π)/22x=kπ/2+π/2-π/32x=kπ/2+π/6x=kπ/4+π/12(对称轴)

T=2∏/w此题中w=1/3故T=2∏÷1/3=6∏

y'=4cos（2x-π/3）≥0,则2kπ-π/2≤2x-π/3≤2kπ+π/2,k∈Z2kπ-π/6≤2x≤2kπ+5π/6,kπ-π/12≤x≤kπ+5π/12,x∈【kπ-π/12,kπ+5π

y=sinx在[0,pai]的单调递减区间为[pi/2,pi];则y=3sin(2x+pai/4)在[0,pai]的单调递减区间为,pi/2《2x+pi/4《pi解得pi/8《x《3pi/8,即[pi

y=sin(1/2x+π/3),x属于R当1/2x+π/3=2kπ+π/2时,y=sin(1/2x+π/3)有最大值1此时x=4kπ+π-2π/3=4kπ+π/3,k∈Z当1/2x+π/3∈【2kπ+