Docstoc

Progressions

Document Sample
Progressions Powered By Docstoc
					Find the sum of n terms of the series whose rth term is...(2r+1)2(to the power r)

Hoping that (2r+1)2(to the power r) means (2r+1)2r=r2r+1+2r= r2r-1+2+2r=4 r2r-1+2r

                    =

       =2[2n-1]

Consider the equation x+x2+x3+ x4 …… xn=                 =

Differentiating with respect to x,

1+2x+3x2+4x3+ 5x4 …… nxn-1=                                       =

On putting x=2, we get

           =

Therefore,

                        =4                ] + 2[2n-1] =2n (4n-2) +2

				
DOCUMENT INFO
Shared By:
Stats:
views:2
posted:9/14/2012
language:English
pages:1
Description: AIEEE IIT-JEE CBSE STUDY MATERIAL MATHEMATICS SAMPLE PAPERS TEST PAPER KEY SOLUTIONS ANSWERS QUESTIONS KEY CONCEPTS