序列的前五个术语是什么? A_N = N ^ 2 + 2

序列的前五个术语是什么? A_N = N ^ 2 + 2
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回答:

如下所示

说明:

对于前几个术语,请插入每个值 #N#

#a_1 = 1 ^ 2 + 2 = 3#

#a_2 = 2 ^ 2 +2 = 4 + 2 = 6#

#a_3 = 3 ^ 2 + 2 = 9 + 2 = 11#

#a_4 = 4 ^ 2 + 2 = 16 + 2 = 18#

#a_5 = 5 ^ 2 + 2 = 25 + 2 = 27#

因此前五个术语是:

#3,6,11,18,27 #

回答:

#3,6,11,18,27#

说明:

#“获取术语替换”n = 1,2,3,4,5“到”a_n#“

#A_1 = 1 ^ 2 + 2 = 1 + 2 = 3#

#A_2 = 2 ^ 2 + 2 = 4 + 2 = 6#

#A_3 = 3 ^ 2 + 2 = 9 + 2 == 11#

#A_4 = 4 ^ 2 + 2 = 16 + 2 = 18#

#A_5 = 5 ^ 2 + 2 = 25 + 2 = 27#