Exercise. Which of the following sequences are geometric sequences for n = 1, 2, 3, ...? an = -3n + 5 an = -5 . 7+4 an = 5n 22n4-1 an = (3) . an-1 where a1 = 10 an An' +n-14 n+2 an = n . cos (2Tn) + 4 an = n . 2n ? Check work