Question

PLEASE HELPO 25 POINTS

Answer 1

an = 1/2 (n) (n+1)

Step by Step Exclamation

1,3,6,10,.........

3-1=2

6-3=3

Each term is different so there is no common difference. It is not an arithmetic sequence

3/1=3

6/3 =2

Each term is different so there is no common ratio. It is not a geometric sequence

1 3 6 10

+2 +3 +4

a1 = 1

a2 = 3

a3 = 6 = 2*3

a4 = 10 = 2*5

Answer 2

an = 1/2 (n) (n+1)

Explanation:

1,3,6,10,.........

3-1=2

6-3=3

Each term is different so there is no common difference. It is not an arithmetic sequence

3/1=3

6/3 =2

Each term is different so there is no common ratio. It is not a geometric sequence

1 3 6 10

+2 +3 +4

a1 = 1

a2 = 3

a3 = 6 = 2*3

a4 = 10 = 2*5