16 terms

an=an-1+d

arithmetic recursive

an=a1+(n-1)d

arithmetic explicit

an=an-1(r)

geometric recursive

an=a1(r)^(n-1)

geometric explicit

When order matters, use... (How many different possibilities?)...

nPr

When order does NOT matter, use... (How many different possibilities?)...

nCr

There are 10 marbles in a bag: 1 red, 1 white, 1 yellow, 2 green, 2 blue, and 3 orange. (How many different possibilities?)

...

(n/2)(2a1+(n-1)d)

arithmetic summation formula

(a1(1-n^r)) / (1-n)

geometric summation formula

In a summation, when i or k is greater than 1... (fill in the blank) Take the normal answer of k=1 and n= the original n, and then find the same summation where k=1 and n is 1 less than the original given k. Then you _______ the summation with the different n from the summation with the original n to find the final answer.

subtract

(n*(n+1))/2

Summation of k

(n*(n+1)(2n+1))/6

Summation of k^2

((n^2)*(n+1)^2)/4

Summation of k^3

limit = (a1)/(1-r)

geometric converging limit

When finding n for a series in order to find the series' summation, what type of geometric/arithmetic formulas can you plug the given numbers in to find n?

explicit

When finding n for a series in order to find the series' summation, what type of geometric/arithmetic formulas should you NOT use to plug in the given numbers in to find n?

recursive