求函数f(x)=cos^2(x-pai/12)+sin^2(x+pai/12)-1的周期
教我一下过程,高一的基本忘了,公式最好也列出来!
谢谢了,各位大虾!
参考资料:团队:我最爱数学!
求函数f(x)=cos^2(x-pai\/12)+sin^2(x+pai\/12)-1的周期
f(x)=cos^2(x-pai\/12)+sin^2(x+pai\/12)-1 =[1+cos(2x-π\/6)]\/2+[1-cos(2x+π\/6)]\/2-1 =[cos(2x-π\/6)-cos(2x+π\/6)]\/2 =(sin2x)\/2 所以最小正周期为π 这里主要公式是二倍角公式和两角和差公式,都是常规公式,书上有 参考资料:团队:我最爱数学!
...\/2+pai\/12)+√3sin(x\/2+pai\/12)cos(x\/2+pai\/12)-1\/2。
首先根据倍角公式,得到 f(x)=[1-cos(x+π\/6)]\/2+根号3sin(x+π\/6)\/2 =根号3sin(x+π\/6)\/2-cos(x+π\/6)\/2+1\/2 =sin(x+π\/6)cosπ\/6-cos(x+π\/6)sinπ\/6+1\/2 =sin(x+π\/6-π\/6)+1\/2 =sinx+1\/2 所以f(x)的值域是[-1\/2, 3\/2]祝你学习愉快,生活幸福O...
已知函数f(x)=cos(2x-pai\/3)+2sin(x-pai\/4).sin(x+pai\/4)求函数在区...
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\/4)cos(x-π\/4)=cos(2x-π\/3)+sin(2x-π\/2)=cos(2x-π\/3)-cos2x =(1\/2)cos2x+(√3\/2)sin2x-cos2x =(√3\/2)sin2x-(1\/2)cos...
已知函数f(x)=cos^2(x+pai\/12)+1\/2sin2x化简?
f(x)=[cos(2x+pi\/6)]\/2+1\/2+1\/2sin2x =cos2xcos(pi\/6)\/2-sin(2x)sin(pi\/6)\/2+1\/2sin2x+1\/2 =根号3\/4*cos(2x) +1\/4sin(2x)+1\/2 =1\/2sin(2x+pi\/3)+1\/2
已知函数fx=cos^2(x-pai\/6)-sin^2
f(x) =[cos(x-π\/6)]^2 - (sinx)^2 = [(√3\/2)cosx + (1\/2)sinx]^2 - (sinx)^2 = (1\/4)( 3(cosx)^2 + 2√3sinxcosx -3(sinx)^2 )= (1\/4) ( 3cos2x + √3sin2x )= (√3\/2)((√3\/2)cos2x+ (1\/2)sin2x)= (√3\/2)sin(2x+π\/3)max f(x) ...
已知函数f(x)=cos(2x-派
f(x)=cos2x*1\/2+sin2x*根号3\/2-cos2x=-1\/2cos2x-根号3\/2sin2x=-cos(2x-Pai\/3)最小正周期T=2Pai\/2=Pai 对称轴方程是2x-Pai\/3=kPai 即有x=kPai\/2+Pai\/6
已知函数f(x)=cos^2x-根号3sinxcosx+1. (1)求函数f(x)的单调递增...
=-sin(2x-pai\/6)+3\/2 t=sin(2x-pai\/6)f(t)=-t+3\/2 f(t)在R上是单调递减的 f(t)的单调递增区间就是t(x)的单调递减区间 2kpai+pai\/2<=2x-pai\/6<=2kpai+3pai\/2 kpai+pai\/3<=x<=kpai+5pai\/6:k:Z [kpai+pai\/3,kpai+5pai\/6](2)f(a)=-sin(2a-pai\/6)+3\/2=...
已知f(x)=cos(2x+派\/3)
f(x)=cos2xcos2Pai\/3+sin2xsin2Pai\/3-cos2x=-1\/2cos2x+根号3\/2sin2x-cos2x=根号3*(sin2x*1\/2-根号3\/2*cos2x)=根号3sin(2x-Pai\/3)故最小正周期T=2π\/2=π 单调增区间是:2KPai-Pai\/2<=2x-Pai\/3<=2kPai+Pai\/2 即是[KPai-Pai\/12,KPai+5Pai\/12](2)f(B\/2)=根号3s...
已知函数f(x)=cos^2(x-π\/6)-sin^2x
f(x)=cos^2(x-π\/6)-sin^2x =(2cos^2(x-π\/6)-1+1)\/2+(1-2sin^2x-1)\/2 =[cos(2x-π\/3)+cos2x]\/2 =(cos2xcosπ\/3+sin2xsinπ\/3+cos2x)\/2 =根号3(2分之根号3倍的cos2x+2分之sin2x)\/2 =根号3\/2sin(2x+π\/3)0<=x<=Pai\/2,则有Pai\/3<=2x+Pai\/3<=4...
关于高中数学一道三角函数题!
得到sin(a+π\/4)=1\/2 又a属于(0,π) 所以a+π\/4属于(π\/4,5π\/4)所以a+π\/4=5π\/6 得到a=7π\/12 (2)x属于[-π\/4,π] 得到x+π\/4属于[0,5π\/4] sin(x+π\/4)属于[-√2\/2,1]得到f(x)属于[-1\/2,√2\/2]所以函数的最大值是√2\/2,最小值是-1...