已知函数f(x)=2sinxcosx+2cos^2x?
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发布时间:2024-10-23 02:45
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时间:2024-11-04 11:54
f(x)=2sinxcosx+2cos^2x
=sin2x+cos2x+1
=√2(√2/2sin2x+√2/2cos2x)+1
=√2sin(2x+π/4)+1
1、求函数的单调增区间
2Kπ-π/2≤2x+π/4≤2Kπ+π/2
Kπ-3π/8≤x≤Kπ+π/4
函数的单调增区间为[Kπ-3π/8,Kπ+π/4]
2、(左加右减)
g(x)=f(x-π/4)=√2sin(2x-π/4)+1
g(x)=1
√2sin(2x-π/4)=0
2x-π/4=2Kπ
x=Kπ+π/8,1,(1) cos^2x=(1+cox2x)/2
f(x)=sin2x+1+cos2x
辅助角公式 f(x)=√2sin(2x+π/4)+1
递增区间-π/2+2kπ≤2x+π/4≤π/2+2kπ,
-3π/8+kπ≤x≤π/8+kπ
递增区间[-3π/8+kπ,π/8+kπ]
(2)g(x)=√2sin[2(x-π/4)+π/4]
=√2sin...,2,我当2cos^2x是cos(2x)了。
fx求导为2cos2x-4sin2x>0求得tan2x<0.5;推出(kπ-π/2<2x (kπ/2-π/4,kπ/2+arctan(0.5)/2)
左加右减,gx=f(x-π/4)=sin(2x-π/2)+2cos(2x-π/2)=-cos2x+2sin2x=1
推出2sc=s^...,2,1,f(x)=2sinxcosx+2cos^2x
=sin2x+cos2x+1
=√2(√2/2sin2x+√2/2cos2x)+1
=√2sin(2x+π/4)+1
1、求函数的单调增区间 由函数的单调性可知,
2Kπ-π/2≤2x+π/4≤2Kπ+π/2 Kπ-3π/8≤x≤Kπ+π/4 k属于整数
函数的...,1,f(x)=sin2x+(1+cos2x)
=sin2x+cos2x+1
=√2sin(2x+π/4)+1
1
把2x+π/4代入到标准的正弦单调增函数中去解出x的过程是:
﹣π/2+2kπ≤2x+π/4≤π/2+2kπ
﹣3π/8+8kπ≤x≤π/8+kπ
单调增区间为:
[﹣3π/8+8kπ ,π/8+kπ],0,1,单调递增【kpi-3pai/8,kpai+pi/8],单调递减为【kpai+pai/8,kpai+5pai/8]
2,x=kpai+pai/8,x=kpai+5pai/8
以上k为整数,0,已知函数f(x)=2sinxcosx+2cos^2x
1:求函数的单调增区间 2:将函数图象向右平移π/4个单位后,得到函数y=g(x)的图象,求方程g(x)=1的解