Practice problem
Which of these is a geometric sequence in recursive form?
an=3n−1a_n = 3^{n-1}an=3n−1
an=3ana_{n} = 3a_{n}an=3an
an=5an−1a_n = 5a_{n-1}an=5an−1
an=7aa_n = 7aan=7a
Type a concept, like “slope” or “photosynthesis”.
