y=1 2sin(1 3x π 6)图象.性质

y=sin(3x+π/12)sin(3x-5π/12)=sin(π/2-3x-π/12)sin(3x-5π/12)=cos(5π/12-3x)sin(3x-5π/12)=cos(3x-5π/12)si

sin(x+y)sin(x-y)=-1/2(cos(x+y+x-y)—cos(x+y-x+y))=-1/2(cos2x—cos2y)=-1/2(1-2（sinx）^2-1+2(siny）^2)=（si

因0≤x≤π/12所以π/6≤2x+π/6≤π/3则y=2sin(2x+π/6)在[0,π/12]上的最大值为2sin(π/3)=√3即y=g(x)在[0,π/12]上的最大值为√3

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

y=sin^4x+cos^4x=sin^4x+cos^4x+2sin^2xcos^2x-2sin^2xcos^2x=（sin^2x+cos^2x）^2-2sin^2xcos^2x=1-1/2sin^2

y=sinx先向左平移π/6,得y=sin(x+π/6)然后,纵坐标不变,横坐标变为原来的1/2,得y=sin(2x+π/6)最后,向上平移3/2,得y=sin(2x+π/6)+3/2

∵x∈（-π/6,π）；　　∴2x+π/3∈（0,2π+π/3）；　　则函数y的最大值为1,最小值为-1；　　则y∈【-1,1】

列表如下：13x-π60π2π3π22πxπ22π7π25π13π2y020-20描点连线如图所示．先列表，再描点连线，可得函数图象．

y'sin(y/x)-y/x*sin(y/x)+1=0令y/x=u,则y'=u+xu'所以(u+xu')sinu-usinu+1=0xu'sinu+1=0-sinudu=dx/x两边积分：cosu=l

可以先把正余弦的平方化成而二倍角关系呀然后再打开括号没有学过二倍角公式么cosx平方等于二分之cos2x加一sinx的平方等于二分之cos2x减一这是公示x变成2x括号里都乘以二再问：详细点

sinx+siny+sinz-sin(x+y+z)=4sin[(x+y)/2]sin[(x+z)/2]sin[(y+z)/2]sinx+siny+sinz-sin(x+y+z)=2sin[(x+y)/

∵0≤x≤π2，∴π6≤x+π6≤2π3；∴当x+π6=π2时，函数取得最大值是y=sin（x+π6）=1；当x+π6=π6时，函数取得最小值是y=sin（x+π6）=12；∴函数y=sin（x+π6

f(x)=sin2(x+y/2)由于sin2x对称轴为π/4+kπ/2;故x+y/2=π/4+kπ/2x=π/4+kπ/2-y/2;将x=x=π/8代入,得y=π/4+kπ,根据y的范围可知：y=-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

通过复合函数求导,可以得到y'=cos(3x-π/6)*3=3cos(3x-π/6)欢迎追问~

令t=2x-π/12,则2x+π/6=2t+π/4,所以y=2sin(2x+π/6)+2sin(2x-π/12)=2sin（t+π/4）+2sint=√2sint+√2cost+2sint=（√2+2

对的,还可以:1.将x坐标向左平移π/6个单位2.将x坐标扩大两倍,y坐标不变

y=sin(x+π/6)sin(x-π/6)+acosx=-1/2[cos(x+π/6+x-π/6)-cos(x+π/6-x+π/6)+acosx=-1/2(cos2x-cosπ/3)+acosx=-

任何正弦函数,只要系数是1,值域就是[-1,1]