What is the sum of the series #1+(1+x)+(1+x+x^2)+(1+x+x^2+x^3)+..."to n terms"#?
1 Answer
Jul 19, 2017
Explanation:
Let
Hence,
or
#=n-(x+x^2+x^3+x^4+.......)# to#n# terms
#=n-(x(1-x^n))/(1-x)#
Hence
Note that if