Given:
A pizza with one topping costs $11. Each additional topping costs $2 more.
To find:
The recursive formula and an explicit formula for the situation.
Solution:
The sequence of costs of pizza is
11, (11+2), (11+2+2), ...
11, 13, 15, ... are in A.P.
Here,
First term: a=11
Common difference: d=2
Explicit formula of an A.P. is
[tex]a_n=a+(n-1)d[/tex]
where, a is first term and d is common difference.
[tex]a_n=11+(n-1)2[/tex]
[tex]a_n=11+2n-2[/tex]
[tex]a_n=9+2n[/tex]
Therefore, the explicit formula for the situation is [tex]a_n=9+2n[/tex].
Recursive formula of an A.P. is
[tex]a_n=a_{n-1}+d[/tex]
Where, [tex]a_1[/tex] is first term and d is common difference.
[tex]a_n=a_{n-1}+2[/tex]
Where, [tex]a_1=11[/tex].
Therefore, the required recursive formula is [tex]a_n=a_{n-1}+2[/tex] where [tex]a_1=11[/tex].
