Ch3 sequences and series Flashcards
1
Q
nth term in arithmetic
A
Un = a + (n-1)d
2
Q
sum of first n terms arithmetic
A
Sn = n/2(2a + (n-1)d)
3
Q
nth term geometric
A
Un = ar ^n-1
4
Q
sum of first n terms geometic
A
a(1-r^n) / 1-r
a(r^n-1) / r-1
5
Q
sum to infinity
A
a/1-r
