x-3x²+5x³……
x-3x²+5x³……
（1）他的弟100项是什么?（2）他的第n（n为正整数）项是什么?（3）当x=1时,求他钱2012项的和.
（1）他的弟100项是什么?（2）他的第n（n为正整数）项是什么?（3）当x=1时,求他钱2012项的和.
数学人气：958 ℃时间：2020-01-27 03:22:26
优质解答
（1）他的弟100项是-199x^100（2）他的第n（n为正整数）项是(-1)^(n+1)*(2n-1)x^n（3）当x=1时,他前2012项的和=1-3+5-7+……+4021-4023=(1-3)+(5-7)+……+(4021-4023)=-2+(-2)+……+(-2)=(-2)×1006=-2012...
我来回答
类似推荐
猜你喜欢
- 1The last problem to be considered at our next meeting is how to invest the money.
- 2my mum is ill she stays in the hospital
- 3一根木棒长12米,截取3分之2后,又截去3分之2米,还剩多少米?
- 456个民族的习俗
- 5求高一的物理试题
- 61/6×（6.75÷5/12-2.4+41/4×22/5）-11/8-0.875．
- 7选择、11.---What's on the____?---There are some horses and cows.A.school B.farm C.home
- 8Inside the car___a driver and his boss
- 9True love needs you to wait for it.Everybody can say that he/she loves you but not each of them can
- 10若实数xy满足x-y 1≥0,x y≥0,x≤0,则z=3“x 2y的最小值是多少