Question

How do you write the first five terms of the arithmetic sequence given `a_1=-2.6, d=-0.4`?

Answer 1

`a_1=-2.6`

`a_2=-3`

`a_3=-3.4`

`a_4=-3.8`

`a_5=-4.2`

Explanation:

We know that :

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

So :

`a_2=-2.6-0.4=-3`

`a_3=-2.6+2*(-0.4)=-3.4`

`a_4=-2.6+3*(-0.4)=-3.8`

`a_5=-2.6+4*(-0.4)=-4.2`

Answer 2

`-2.6,-3.0,-3.4,-3.8,-4.2`

Explanation:

`"to obtain the terms add the common difference d to"`
`"each preceding term"`

`a_1=-2.6`

`a_2=-2.6-0.4=-3.0`

`a_3=-2.2-0.4=-3.4`

`"and so on for remaining terms"`