Series Flashcards
1
Q
Describe sigma notation
A
“Σf(r), r=a to b” means to go through all integers between a and b (inclusive) and add f(r) to the running total
2
Q
What is the formula for the sum of the first n natural numbers?
A
n(n+1)/2
3
Q
How can Σf(r), r=a to b where a≠1 be split up?
A
(Σf(r), r=1 to b)-(Σf(r), r=1 to a-1)
4
Q
How can Σ(f(r)+g(r)), r=a to b be split up?
A
(Σ(f(r)), r=a to b)+(Σ(g(r)), r=a to b)
5
Q
How can Σ(n*f(r)), r=a to b be split up, where n is a constant?
A
nΣf(r), r=a to b
6
Q
What is the formula for the sum of the first n square numbers?
A
n(n+1)(2n+1)/6
7
Q
What is the formula for the sum of the first n cube numbers?
A
n²(n+1)²/4
