Arithmetic progression:
Progression's elements:
a1,
a2,
a3, ... ,
an
Progression's denominator:
d
Progression's element calculation formulas:
Progression's n-th element calculation formula:
an =
a1 +
(n − 1) d
Sum of the first n-elements of progression formulas:
Geometric progression:
Progression's elements:
b1,
b2,
b3, ... ,
bn
Progression's denominator:
q, if
| q | < 1,
then progression is called infinitely decreasing progression
Progression's element calculation formulas:
Progression's n-th element calculation formula:
Sum of the first n-elements of progression formula:
Sum of the infinitely decreasing progression's formula: