The sum of a sequence (Posted on 2004-12-14)

	Submitted by Mohammad
Rating: 3.4286 (7 votes)
Solution:	(Hide)
Let S=1+2x+3x2+4x3+...nxn-1; the answer to this problem is S times x. S= (1+x+x2+...+xn)'= [(1-x^n+1)/(1-x)]'= (nxn+1-(n+1)xn+1)/(1-x)2.

	Subject	Author	Date
	answer	K Sengupta	2008-02-18 14:50:49
	Let the record show- another non-calculus variation	JayDeeKay	2007-06-15 13:22:00
	easy	Pemmadu Raghu Ramaiah	2005-01-24 19:27:55
	Without calculus	Federico Kereki	2004-12-15 11:22:23
	A non-calculus solution	Richard	2004-12-15 00:41:42
	all the solutions need...	Charlie	2004-12-14 18:35:20
	re: Solution	Charlie	2004-12-14 18:28:11
	solution	Charlie	2004-12-14 18:08:42
	Solution	Old Original Oskar!	2004-12-14 17:49:25
	calculus solution	Richard	2004-12-14 17:41:22