黑心天nn
幼苗
共回答了18个问题采纳率:100% 举报
f(x)=sin(2x+派/4)+cos(2x+派/4) =sin2xcos(π/4)+cos2xsin(π/4)+cos2xcos(π/4)-sin2xsin(π/4) =√2cos(2x)(1)2x=kπ对称轴:x=kπ/2(2)增区间 2kπ-π≤2x≤2kπkπ-π/2≤x≤kπ增区间[kπ-π/2,kπ],k∈Z减区...
1年前
追问
5
longgu
举报
=sin2xcos(π/4)+cos2xsin(π/4)+cos2xcos(π/4)-sin2xsin(π/4) =√2cos(2x) 这个……是怎么整理的……
举报
黑心天nn
=sin2xcos(π/4)+cos2xsin(π/4)+cos2xcos(π/4)-sin2xsin(π/4) =(√2/2)sin2x+(√2/2)cos2x+(√2/2)cos2x-(√2/2)sin2x =√2cos2x