sin(2x+派/3)转换成cos(2x-派/6)

根据诱导公式,sin(x-3π/2)cos(π-x)tan(π+x)=(cosx)(-cosx)(-tanx)=sinxcosx,∵sinx=3/5,∴cosx=±4/5,原式=±12/25.

f(x)=2根号3sin(x/2+派/4)cos(x/2+派/4)-sin(x+派).=（根号3）sin（x+π/2）-sin（x+π）=（根号3）cosx+sinx这一步用到诱导公式=2*（（根号3

y=sin(2x-π/3)x∈[π/6,π/2]所以2x-π/3∈[0,2π/3]当2x-π/3=0即x=π/6时函数y有最小值为0当2x-π/3=π/2即5π/12时函数y有最大值为1所以值域为【0

原式=1/2sinx+根号3/2cosx+sinx-根号3cosx+根号3/2cosx-3/2sinx（先全部展开）=0（最后合并同类项得0）

2)f=1/2=sin(x)=kπ+π/6or2kπ+π/62n项和,可分奇数n项和偶数n项s奇=a1n+n(n-1)d/2=π*n/6+π*n(n-1)=π(n^2-5n/6)s偶=a1n+n(n-

sin(π-x)+sin(π+x)-cos(-x)+cos(2π-x)-tan(π+x)cot(π-x)=-sin(-x)-sin（x）-cos(x)+cos(-x)-[-tan(x)][-cot(-

f(x)=2根号3sin(x/2+派/4)cos(x/2+派/4)-sin(x+派).=√3sin(x+π/2)+sinx=sinx+√3cosx=2(1/2sinx+√3/2cosx)=2sin(x

sin(2派-x)tan(派+x)cot(-x-派)/tan(3派-x)cos(派-x)=-sinxtanxcot(-x)/tan(-x)(-cosx)=sinxtanxcotx/tanxcosx=s

sinx=-5/13x∈(П,3П/2)cosx=√1-(-5/13)^2=-12/13sin(x-П/4)=sinxcosП/4-cosxsinпП/4=√2/2(-5/13+12/13)=7√2/

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

才5分==再问：提高了再答：1、π；5/2,1/22、-π/12再问：第二个问能详解一下么？谢再答：奇函数的话就意味着有一个对称中心（0,0），这时是最小的

原式=4sinx+4sin【π-（2π/3-x）】=4sinx+4sin（x+π/3）（拆开）=4sinx+4（sinxcosπ/3+cosxsinπ/3）=4sinx+4（1/2sinx+√3/2c

π/6+2kπ

原式=(sinx•(-sinx)•tanx)/(cosx•(-tanx)•cosx)=sin²x/cos²x=tan²x

得x=4kπ（k为整数）或x=4π/3+4kπ（k为整数）.代入求得cos(x+π/3)的值为1/2或-1/2

令F’(x)=√3cos2x+sin2x=0,x1=kπ/2-π/6(k为偶数),x2=kπ/2-π/6(k为奇数)∴f(x)在x1极小,在x2处取极大值∴f(x)单调递减区间为[kπ/2-π/6,（

sin(x+π/3)sin(x+11π/6)=1/2则有：sin(x+π/3)sin[(x-π/6)+2π]=1/2sin(x+π/3)sin(x-π/6)=1/2-----(1)由于：sin(x+π

f(x)=sin(π-x)cos(2π-x)/sin(π/2+x)tan(π+x)=sinxcosx/cosxtanx=cosxf（31π/3）=cos(10π+π/3)=cosπ/3=1/2再问：它

f(x)=2√3sin(x/2+π/4)cos(x/2+π/4)-sin(x+π)=√3sin(x+π/2)+sinx=√3cosx+sinx=2sin(x+π/3),(1)2π.(2)g(x)=2s

f(x)=2sin2(π/6x)+sin(π/3x+π/6)-1=sin(π/3x+π/6)-[1-2sin2(π/6x)]=sin(π/3x+π/6)-cos(π/3x)=sin(π/3x)*cos