Question

What is the difference between arithmetic and geometric?

Answer 1

in arithmetic
\[common ~difference~d=a _{n}-a _{n-1}\]
or every term is obtained by adding common difference to preceding term.
In geometric every term is obtained by multiplying a common ratio to preceding term. or
\[common~ratio~r=\frac{ a _{n} }{ a _{n-1} }\]