3sinπx-log1 2x

sin³x-sin^5x=sin³x(1-sin²x)=sin³xcos²x当00√(sin³xcos²x)=sinxcosx√s

2sin^2[(π/4)+x]+根号3（sin^x-cos^x）-1=-(1-2sin^2[(π/4)+x)-√3cos2x=-cos(π/2+2x)-√3cos2x=sin2x-√3cos2x=2[

(1)f(x)=√3(1-cos2x)-1/2sin2x+√3/2cos2x=√3-1/2sin2x-√3/2cos2x=√3-sin(2x+π/3)∴最小正周期T=2π/2=π单调增区间：π/2+2

y＝sin(x+π3)sin(x+π2)＝(sinxcosπ3+cosxsinπ3)cosx=12sinxcosx+32cos2x＝14sin2x+32•1+cos2x2=34+12sin(2x+π3

∵f（x）=[-sinx(-sinx)cos(π+x)]／[-2cosxsin(π-x)]=[sin²x(-cosx)]／(-2cosxsinx)=1/2sinx∴最小正周期T=2π∴函数图

令a=π-x则a趋于0sin3x=sin(3π-3a)=sin3asin2x=sin(2π-2a)=-sin2a所以原式=-lim(a→0)sin3a/sin2asin3a和sin2a的等价无穷小是3

f(x)=2cos*sin(x+π/3)-^3sin^2x+sinx*cosx=2cosx(1/2sinx+√3/2cosx)-^3sin^2x+sinx*cosx=sin2x+√3cos2x=2si

sin(x+π/6)=1/3sin(5π/6-x)=sin[π-(x+π/6)]=1/3sin^2(π/3-x)=sin^2[π/2-(x+π/6)]=cos^2(x+π/6)=1-sin^2(x+π

f(x)=2√3sin²x-sin(2x-π/3)=√3-√3cos2x-1/2sin2x+√3/2cos2x=√3-(1/2sin2x+√3/2cos2x)=√3-sin(2x+π/3)T

fx=2cosx(0.5sinx+根号3/2cosx)-根号3sin*2x+sinxcosx=2sinxcosx+根号3（cos*2x-sin*2x）=sin2x+根号3cos2x=2sin（2x+派

sin(x+π)=-ainx用诱导公式：x+π是第三象限的角,第三象限的角的正弦为负,π是1/2π的偶数倍,不改变函数名sin(x+3/2π)=-cosx用诱导公式：x+3/2π是第四象限的角,第四象

sin(2x+π/3)

（Ⅰ）设x＜0时，则−x＞0⇒f(−x)＝log12(−x)⇒f(x)＝−f(−x)＝−log12(−x)．所以：当x＜0时，f（x）=-log 12（-x）．（Ⅱ）由题意，得x＞0log1

f(x)=sin^2x+2√3sinxcosx+sin(x+π/4)sin(x-π/4)=(1-cos2x)/2+√3sin2x+(1/2)2sin(x-π/4)cos(x-π/4)=2-2cos2x

原式=sin（x+π/3）+√3cos（x+π/3）+2sin（x-π/3）=2[1/2sin(x+π/3)+√3/2cos(x+π/3)]+2sin(x-π/3)=2sin(x+π/3+π/6)+2

因为函数f(x)＝3sinπ2x−log12x的零点个数就是对应的函数y=3sinπ2x与y=log 12x的交点个数．又因为函数y=3sinπ2x的周期T=2ππ2=4．而y=log&nb

∵√3/2-√3sin²x+sinxcosx=(√3/2)(1-2sin²x)+(1/2)sin2x=sin(π/3)cos2x+cos(π/3)sin2x=sin(2x+π/3)

由题意x∈[0，π2]，得x+π3∈[π3，5π6]，∴sin（x+π3）∈[12，1]∴函数y=sin（x+π3）在区间[0，π2]的最小值为12故答案为12

-cosx

（1）化解函数：√3∵f(x)=sin²wx+√3sinwxcoswx+2cos²wx=√3/2sin2wx+sin²wx+cos²wx+cos²wx