Question

What is the recursive rule for the sequence?

Answer 1

`a_n=a_(n-1) - 13.8 \: where \: \: a_1 = - 7.4`

Step-by-step explanation

The given sequence is

-7.4, -21.2,-35,-48.8,-62.6,...

The first term of this sequence is

`a_1=-7.4`

The constant difference can be calculated using any two consecutive terms:

`d = - 35 - - 21.2 = - 13.8`

The recursive rule is given by;

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

We plug in the values to get,

`a_n=a_(n-1) + - 13.8`

`a_n=a_(n-1) - 13.8 \: where \: \: a_1 = - 7.4`

The correct choice is A.