Question

Find the first 5 terms of the sequence an defined below.

Answer 1

Answer:

Step-by-step explanation:

A_n = a + (n-1)d

a_n = -2n + 3

when n=1

a_1 = a = -2(1) + 3 = -2 + 3 = 1

when n = 2

a-_2  = -2(2) + 3 = -4 +3 = -1

a_2 = a + d

therefore,

a + d = -1

d = -1 - a

d = - 1 - 1

d = -2

Therefore the sequence is ,

1 , -1, -3, -5, -7.......

Answer 2

Answer:

a_1=-3  a_2= -4  a_3=-3    a_4=-6   a_5=-7

Step-by-step explanation:

We have to find first 5 terms of sequence.  It means that n =1 or 2or3 or4 or 5

Only n=3 of them is divisible by 3 .  n=1 ,2,4 and 5 are not divisible by 3.

So in case n=3 we have to find a_3 using formula  a_n=-2n+3

In all other cases we have to use formula a_n= -n-2.

Lets do it !

a_1= -1-2=-3

a_2=-2-2= -4

a_3=-2*3+3=-6+3=-3

a_4=-4-2=-6

a_5=-5-2=-7