What is the nth term of the sequence below? 2, 6, 12, 20, . . 3n n^2 - 1 n^2 + 1 n (n+ 1)

  n(n+1)

Step-by-step explanation:

Only the last two formulas work for n=1; only the last formula works for n=2.

For n=1

  3n = 3 ≠ 2

  n² -1 = 0 ≠ 2

  n² +1 = 2

  n(n+1) = 2

For n=2

  n²+1 = 5 ≠ 6

  n(n+1) = 6 . . . . . this last formula works for the given sequence

false.

step-by-step explanation:

false.

cavalieri's principle makes that statement about the volumes, not about the areas.