# data[].attributes.body
f(n)= -4n+1

It is how you go from the x column to y

# data[].attributes.body
f(1)=-3   f(n)=f(n-1)-4

This is recursive because it is subtracting 4 each time.

# data[].attributes.body
this table is linear because the first difference is constant, it subtracts 4 every time.

# data[].attributes.body
1   |   -3

2   |   -7

3   |   -11

4   |   -15

5   |   -19

# data[].attributes.body
In order to find the explicit, you have to find the difference between f(n) and f(n-1).
f(n)=n^2-4

# data[].attributes.body
f(1)=-3

f(n)=f(n-1)+2n-1

First, you have to find f(1). Then, you have to find how to get from f(n-1) to f(1)

# data[].attributes.body
n | f(n)

1 | -3

2 | 0

3 | 5

4 | 12

5 | 21

# data[].attributes.body
The 2nd difference is constant which shows that this is a quadratic model

# data[].attributes.body
This table to the left is exponential because there is a common ratio

# data[].attributes.body
To find the recursive equation you need to find the first difference between two y values. In this model the recursive equation is, f(0)=2
f(n)=f(n-1)*2

# data[].attributes.body
To get this explicit equation you must find how to get from x to y. The explicit equation for the model above is,
f(n)= 2^n+1

# data[].attributes.body
n          |         F(n)
0          |          2
1          |          4
2          |          8
3 | 16

# data[].attributes.attachment_link.description
How to write quadratic recursive equations.