Question

What are the first four terms of the sequence modeled by the recursive formula an=an-1+5 when a1=-3?

A) –3, –8, –13, –18
B) –3, 2, 7, 12
C) –3, –15, –75, –375
D) –3, 1, 5, 9

Answer 1

b . _3,2,7,12

Explanation:

Answer 2

Given sequence:
`a_n=a_(n-1)+5`

`a_1= -3.`.

We need to find first four terms of the sequence.

We already given first term -3.

Let us find second term
`a_2`.

Plugging n=2.

`a_2=a_(2-1)+5 = a_1+5= -3+5 = 2.`

Now taking n=3.

`a_3=a_(3-1)+5 = a_2+5= 2+5 = 7`.

Now, n=4.

`a_4=a_(4-1)+5 = a_3+5= 7+5 = 12`.

We got terms -3, 2, 7 and 12.

Therefore, correct option is B) –3, 2, 7, 12.