The explicid formula of an arithmetic sequence:
[tex]a_n=a_1+(n-1)d[/tex]
We have
[tex]a_1=2,\ d=-4[/tex]
Substitute:
[tex]a_n=2+(n-1)(-4)[/tex] use distributive property
[tex]a_n=2+(-4n)+(-1)(-4)\\\\a_n=2-4n+4\\\\\boxed{a_n=6-4n}[/tex]
The recursive formula of an arithmetic sequence:
[tex]\left\{\begin{array}{ccc}a_1=a_1\\a_n=a_{n-1}+d\end{array}\right[/tex]
Substitute:
[tex]\left\{\begin{array}{ccc}a_1=2\\a_n=a_{n-1}-4\end{array}\right[/tex]
