风戒指
幼苗
共回答了19个问题采纳率:78.9% 举报
(1) w=1时f(x)=sinx-cos(x+π/2)=sinx-cosx cos(π/2)+sinxsin(π/2)=2sinx
f(x)最大值是2,此时x∈{π/2+2kπ|k取整数}
最小值时-2,此时x∈{3π/2+2kπ|k取整数}
(2)f(x)=sinwx-coswx cos(π/2)+sinwxsin(π/2)=sinwx+sinwx=2sinwx
f(π/3)=√3,所以2sin(wπ/3)=√3
wπ/3=π/3或者2π/3
w最小正值取1
1年前
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