停泊港湾
幼苗
共回答了22个问题采纳率:95.5% 举报
答:只要求f(x)表达式吗?
锐角a满足:tana=√2-1>0
tan(2a)=2tana /(1-tan²a)
=2(√2-1) /[1-(√2-1)²]
=2(√2-1)/(2√2-2)
=1
所以:2a=π/4,a=π/8
f(x)=2xtan(2a)+sin(2a+π/4)
=2x+sin(π/4+π/4)
=2x+1
所以:f(x)=2x+1
An数列首项A1=1
A(n+1)=f(An)=2An +1
A(n+1)-An=An +1
1年前
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