f(x)=sin(x+π/6)+sin(x-π/6)+cosx 的单调递增区间

来源:学生作业帮助网 编辑:作业帮 时间:2024/11/05 16:04:47
f(x)=sin(x+π/6)+sin(x-π/6)+cosx 的单调递增区间
x)KӨд-Ө>ߠo fB gXHPl`'@@7(<7]"h5Є0G[ {Ɏ]a~qAb(D

f(x)=sin(x+π/6)+sin(x-π/6)+cosx 的单调递增区间
f(x)=sin(x+π/6)+sin(x-π/6)+cosx 的单调递增区间

f(x)=sin(x+π/6)+sin(x-π/6)+cosx 的单调递增区间
f(x)=sin(x+π/6)+sin(x-π/6)+cosx=2sinxcosπ/6+cosx=√3sinx+cosx=2(√3/2sinx+1/2cosx)
=2sin(x+π/6)
令x+π/6=-π/2+2kπ 得 x=-2π/3+2kπ
令x+π/6=π/2+2kπ 得 x=π/6+2kπ
∴ 单调增区间为〔-2π/3+2kπ,π/6+2kπ〕