Summations Flashcards
1
Q
nΣk=0 ar^k (r != 0)
A
= (ar^(n+1) - a) / (r - 1)
2
Q
nΣk=1 k
A
n(n+1) / 2
3
Q
nΣk=1 k^2
A
n(n+1)(2n+1) / 6
4
Q
nΣk=1 k^3
A
n^2 (n+1)^2 / 4
5
Q
inf Σk=0 x^k
A
1/ (1-x)
6
Q
inf Σk=1 kx^(k-1)
A
1 / (1-x)^2
