魏家小Kin
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共回答了19个问题采纳率:94.7% 举报
先化简,再求值.
f(x)=(1/2)2sinx*cosx+√3*cosx^2
=1/2sin2x+√3/2(2cos^2-1)+√3/2
=1/2sin2x+√3/2cos2x+√3/2
=cos60sin2x+cos2xsin60+√3/2
=sin(2x+π/3))+√3/2
T=2π/w=2π/2=π
所以最小正周期是π
(2)sin的原单调增区间是(-π/2+2kπ,π/2+2kπ)减区间(π/2+2kπ,3π/2+2kπ)
f(x)的增区间为(-5π/12+kπ,π/12+kπ)减区间(π/12+kπ,7π/12+kπ)
由图像可知π/2时最小,
代入得最小值0,最大1+√3/2
1年前
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