arimentic sequences formula Flashcards
1
Q
for nth term
A
A + (n-1)d
2
Q
find the number of the first n terms
A
n/2 (2a + (n-1)D)
3
Q
find the number of the first n terms with l
A
n/2 (a+l)
4
Q
nth term of geometric sequences
A
ARn-1
5
Q
the possible value
A
U2/U1 = U3/U2
6
Q
covergent serices
A
if 1 is greater than R
7
Q
sum to infinity
A
a/1-r
a(1-rn)/1-r
