计算 (a-b)^2n - 2(b-a)^2n-1 - 2/3 (b-a)^2n - 1/2(a-b)^2n-1其中a=b-1 ,b为正整数.得数是-7/6 还是 1/6?
来源:学生作业帮助网 编辑:作业帮 时间:2024/05/19 11:22:42
计算 (a-b)^2n - 2(b-a)^2n-1 - 2/3 (b-a)^2n - 1/2(a-b)^2n-1
其中a=b-1 ,b为正整数.
得数是-7/6 还是 1/6?
∵a=b-1
∴a-b=-1
(a-b)^2n - 2(b-a)^(2n-1)- 2/3 (b-a)^2n - 1/2(a-b)^(2n-1)
=(a-b)^2n+2(a-b)^(2n-1)-2/3(a-b)^2n-1/2(a-b)^(2n-1)
=1/3(a-b)^2n+3/2(a-b)^(2n+1)
=1/3(-1)^2n+3/2(-1)^(2n+1)
=1/3-3/2
=2/6-9/6
=-7/6
a=b-1
a-b=-1
(a-b)^2n - 2(b-a)^2n-1 - 2/3 (b-a)^2n - 1/2(a-b)^2n-1
=(a-b)^2n + 2(a-b)^2n-1 - 2/3 (a-b)^2n - 1/2(a-b)^2n-1
=1/3(a-b)^2n+3/2(a-b)^2n-1
=1/3-3/2
=-7/6=(a-b)^2n + 2...
全部展开
a=b-1
a-b=-1
(a-b)^2n - 2(b-a)^2n-1 - 2/3 (b-a)^2n - 1/2(a-b)^2n-1
=(a-b)^2n + 2(a-b)^2n-1 - 2/3 (a-b)^2n - 1/2(a-b)^2n-1
=1/3(a-b)^2n+3/2(a-b)^2n-1
=1/3-3/2
=-7/6
收起
[(a^2*a^n)^2(b^n*b)]^2计算
数列极限计算计算lim((a+b)/ab + (a^2+b^2)/a^2b^2 + … +(a^n+b^n)/a^nb^n)
计算:(a-b)^2n+1(b-a)^2n÷(b-a)^2n+2
一道很简单的计算,(a-b)^2*(a-b)^n*(b-a)^5
计算(-a^m*b^n)^2=
计算(a^n+b)(a^n-b)
计算:(a-b)^2·(b-a)^2n÷(a-b)^2n-1
计算a^n=2 b^n=3 a^2n+b^3n=( )
计算(a-b)^2(a-b)^n(b-a)^5(n是整数)
计算 (3A^N+2*B-2A^N*B^N-1+3B^N)*5A^N*B^N+3(N为正整数,n>1)
计算(a-b)^m×(a-b)^n×(b-a)^2n÷(b-a)^2m+1(m.n为正整数)(要过程)
计算-(m^a*n^b)^2*(m^2*n)^3
计算[(a+b)^2-(a+b)]*(a+b)
已知a=-b,m=1/n,计算(a+b)n/m+(-2m)*n的值
计算:(a^n b^4)³·a^5 b^2n-9 -(a^n+1 b)³·(ab^n)²
计算:(a-b)^5(b-a)^2n+1(b-a)^2
计算 (a-b)^2n - 2(b-a)^2n-1 - 2/3 (b-a)^2n - 1/2(a-b)^2n-1其中a=b-1 ,b为正整数.得数是-7/6 还是 1/6?
(3a^n+2b-2a^nb^n-1+3b^n)·5a^nb^n+3计算