mingtianhaizai
幼苗
共回答了19个问题采纳率:84.2% 举报
f(x)=2cosxsin(π/2+x)+sin2x-cos2x =-2(cosx)^2+sin2x-cos2x =1/2+sin2x
(1)f(π/8)=1/2+sin(π/4)=1/2+√2/2;
(2)y=f(wx)在[-π/3,π/4]上单调递减,求w的取值范围.
y=f(wx)=1/2+sin((2wx),单调递减区间为[π,3π/2],2wπ=-π/3,w=-1/6,2w*3π/2=π/4,w=1/12,所以w的取值范围为[-1/6,1/12].
1年前
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