Question

What is the nth term in this sequence 1.5,3,4.5,6,7.5

Answer 1

The pattern is to add 1.5


1, 1.5
2, 3
3, 4.5
4, 6
5, 7.5

1 + (0.5*1) = 1.5
2 + (0.5*2) = 3
3 + (0.5*3) = 4.5
4 + (0.5*4) = 6
5 + (0.5*5) = 7.5

f(n) = n + (0.5*n)

Answer 2

1.5, 3, 4.5, 6, 7.5

We need to find the pattern first.

3 - 1.5 = 1.5
4.5 - 3 = 1.5
6 - 4.5 = 1.5
7.5 - 6 = 1.5

So the pattern is 1.5
We plug it into the formula:


`a_n = a_1 + (n-1)d`


`a_n = 1.5 + (n-1) 1.5\\a_n = 1.5 + 1.5n - 1.5\\a_n = 1.5 - 1.5 + 1.5n\\a_n =1.5n`

So, we can find the nth term in the sequence using the formula:

`a_n = 1.5n`