★ Arithmetic Progression [ Explicit and Recursive notation ] ★
Arithmetic Sequence - 19 , 9 , -1 ...
Recursive Notation -
First term = 19
Common difference = -10
In subscript notation - [ a₁ = 19 , aₙ = aₙ-₁ -10 ]
In functional notation - f(n) = f (n -1) -10
Explicit Notation - f ( n ) = f ( 1 ) + d ( n - 1 )
= 19 - 10 ( n -1 )
= 29 - 10n
It's functional and subscript notations resides the same