a1= (which is the first term.)
to find the 2nd term you plug in 2 for (an) in the formula given to you. =-4(2-1)^2 *remember an represents the term u are looking for *
now you start to solve it
-4(2-1)^2
-4 (1)^2
. -4^2
= 16
so your first two terms are 2 and 16 .