Precalc 12.1-12.2 quiz

k sum of sequences

(n(n+1))/2

k² sum of sequences

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

k³ sum of sequences

(n²(n+1)²)/4

sum of first n terms of an arithmetic sequence

(n/2)(a₁+a_n)

sum of first n terms of a geometric sequence

a₁*((1-rⁿ)/(1-r))

sum of an infinite geometric sequence

a₁/(1-r)

(n)

(j )

n!/(j!(n-j)!)