已知函数f(x)=2√3sinx·cosx+cos^2x-sin^2x-1(x∈R)

(1)求单调递增区间
(2)若x∈[-5pai/12,pai/3]
第二步要求详细点

答:
f(x)=2√3sinxcosx+cos²x-sin²x-1
=√3sin2x+cos2x-1
=2*[sinx(√3/2)+cos2x(1/2)-1
=2sin(x+π/6)-1

(1)f(x)=2sin(x+π/6)-1的单调增区间满足:-π/2+2kπ<=x+π/6<=π/2+2kπ
所以:函数的单调增区间为[2kπ-2π/3,2kπ+π/3],k∈Z

(2)若-5π/12<=x<=π/3
则:-π/4<=x+π/6<=π/2
所以:-√2/2<=sin(x+π/6)<=1
所以:-√2<=2sin(x+π/6)<=2
所以:-1-√2<=f(x)<=1
所以:f(x)的值域为[-1-√2,1]
温馨提示:内容为网友见解,仅供参考
无其他回答

已知函数f(x)=2√3sinx×cosx+2cos²x-1(x∈R)
已知函数f(x)=2√3sinx×cosx+2cos²x-1(x∈R)<1>求函数f(x)的最小正周期及在区间[0,π\/2]上的最值 <2>若f(x0)=6\/5,x0∈[π\/4,π\/2],求cos2x0的值 (1)解析:∵函数f(x)=2√3sinxcosx+2cos²x-1=√3sin2x+cos2x=2sin(2x+π\/6)∴f(x)的最小正周期...

已知函数f(x)=2√3sinxcosx+cos^2x-sin^2x-1 求周期和递增区间_百度知 ...
f(x)=2√3sinxcosx+cos^2x-sin^2x-1 f(x)=√3sin2x+cos2x-1 =sin(2x+π\/6)-1 所以周期为:T=2π\/w=π.

已知函数f(x)=2√3sinxcosx+2cosxcosx-1(x属于R)
因为x属于[0,π\/2],所以得:2x+π\/6属于[π\/6,7π\/6],则sin(2x+π\/6)就属于[-1\/2,1]所以:f(x)=2sin(2x+π\/6)就属于[-1,2]即最大值为2,最小值为-1;(2)f(Xo)=2sin(2x0+π\/6)=6\/5,所以:sin(2x0+π\/6)=3\/5;因为Xo∈「π\/4,π\/2」所以2x0+π\/6...

已知函数f(x)=2√3sinxcosx+2cos²x-1(x∈R)
f(x) = 2√3sinxcosx+2cos²x-1 = √3 * ( 2sinxcosx) + (2cos²x-1)= 根号3 sin2x + cos2x = 2 (sin2xcosπ\/6+cos2xsinπ\/6)=2 sin(2x+π\/6)最小正周期:2π\/2 = π 在区间[0,π\/2]x ∈[0,π\/2]2x ∈[0,π]2x+π\/6 ∈[π\/6,π+π\/6...

已知函数f(x)=2√3sinxcosx+2cos²x-1(x∈R),求函数f(x)在区间...
f(x)=√3sin2x+cos2x=2 (√3\/2sin2x+1\/2cos2x)=2 (cosπ\/6sin2x+sinπ\/6cos2x)=2sin(2x+π\/6)因为x∈ [0,π\/2]所以2x+π\/6∈ [π\/6,7π\/6]所以sin(2x+π\/6)∈ [-1\/2,1]所以2sin(2x+π\/6)∈ [-1,2]所以函数f(x)在区间[0,π\/2]上的最大值是2和最...

已知函数fx=2√3sinxcosx+2cosx-1(x∈R)
1):fx=2√3sinxcosx+2cos^2 x -1 =√3sin2x+cos2x =2(√3\/2 sin2x +1\/2 cos2x)=2sin(2x+π\/6)所以最小正周期是π 2kπ-π\/2《2x+π\/6《2kπ+π\/2 kπ-π\/3《x《kπ+π\/6 单调增区间 [kπ-π\/3,kπ+π\/6] k∈Z K=0,[-π\/3,π\/6]故在【0...

已知函数f(x)=2根号3sinxcosx+2cosx平方-1。x属于R。求函数f(x)的最...
f(x)=2sinxcosx 2cosx的平方-1 =sin(2x) cos(2x)=根号2[根号2\/2·sin(2x) 根号2\/2·cos(2x)]=根号2[cos(π\/4)·sin(2x) 根号2\/2·cos(2x)]=根号2sin(2x π\/4)=根号2sin(2π 2x π\/4)=根号2sin[2(π x) π\/4];所以f(x)的最小正周期是π.

已知函数fx=2根号3sinxcosx+2sin方x-1,x∈R.求函数fx的最小正周期和单 ...
f(x)=2√3sinxcosx+2sin^2x-1=√3sin2x-cos2x=2sin(2x-π\/6)最小正周期T=π ,单调递增区间:2kπ-π\/2<2x-π\/6<2kπ+π\/2, :kπ-π\/6<x<kπ+π\/3 将函数y=2sin(2x-π\/6)的图像上个点的纵坐标保持不变,横坐标缩短到原来的½,得y=2sin(4x-π\/12)再把所得的...

已知函数f(x)=2√\/3sinx cosx+2cos²x—1(x∈R) (1)求函数f(x)的最...
函数f(x)最大值2,最小值-√3 f(x0)=2sin(2x0+π\/3)=6\/5 sin(2x0+π\/3)=6\/10=0.6 sin(2x0)cosπ\/3+cos(2x0)sinπ\/3=0.6 sin(2x0)*1\/2+cos(2x0) *√3\/2=0.6 cos(2x0+π\/3)=0.8 cos(2x0)cos(π\/3)-sin(2x0)sin π\/3=0.8 cos(2x0)*1\/2...

求解f(x)=2√3sinXcosX+2cos²X-1(X∈R),则f(x)的最小正周期是( )
f(x)=2√3sinXcosX+2cos²X-1 =√3sin(2X)+cos(2X)=2sin(2X+π\/6)T=(2π)\/2=π 答案:A

相似回答
大家正在搜