循环数列1,2,3,4,1,2,3,4.的通项公式是什么?
问题描述：
循环数列1,2,3,4,1,2,3,4.的通项公式是什么?
用一个表达式解决
就是要用整数解决了……不过写出来看看也行啊～
答
An=2.5-SIN((2n-1)/4)×(COS((2n-1)/4)+2^0.5)由SIN((2n-1)/4)得出(1/2)^0.5,(1/2)^0.5,-(1/2)^0.5,-(1/2)^0.5由COS((2n-1)/4)+2^0.5得出3/2×2^0.5,1/2×2^0.5,1/2×2^0.5,3/2×2^0.5相乘得1.5,0.5,-0.5,-1.5用2.5...