Do $1, -1, -3, -5, \ldots$ form an $AP$? If they form an $AP$,write the next two terms.

(A) To check if the sequence forms an $AP$,we calculate the common difference $d = a_{k+1} - a_k$ for consecutive terms:
$a_2 - a_1 = -1 - 1 = -2$
$a_3 - a_2 = -3 - (-1) = -3 + 1 = -2$
$a_4 - a_3 = -5 - (-3) = -5 + 3 = -2$
Since the difference $d = -2$ is constant,the given sequence forms an $AP$.
The next two terms are calculated by adding the common difference $d = -2$ to the last term:
Next term $1 = -5 + (-2) = -7$
Next term $2 = -7 + (-2) = -9$
Thus,the next two terms are $-7$ and $-9$.