Given the following two formulas for an arithmetic sequence, which of the statements below are true

Check all that apply.

The explicit formula: an = a1 + (n - 1) * d

The recursive formula: an = an-1 + d



A.n is the index of the sequence
B.a1 is the previous term in the sequence
C.a1 is the first term in the sequence
D.an-1 is the nth term in the sequence
E.an is the previous term in the sequence

a_1 is the first term.
a_n is the nth term.
a_n-1 is the previous term.
d is the common difference.

From that we gather that C must be true. I do apologise for offering no expertise regarding A; I have never heard of the index of a sequence before. Hopefully someone else knows!