Question

Write down the first five terms of each of the following sequences, where the nth term are given:

a) 5n
b) 2n-2
c) 3n+4
d) n (n+1)
e) n2 ( 2 is the power )​

Answer 1

Answer:

a

n=3n+2 maybe helpful for you

Answer 2

Answer:

a) 5n

⇒an = 5n

→a1 = 5(1)

→a1 = 5

⇒a2 = 5(2)

→a2 = 10

⇒a3 = 5(3)

→a3 = 15

⇒a4 = 5(4)

→a4 = 20

⇒a5 = 5(5)

→a5 = 25

∴the first five terms are 5,10,15,20,25

b) 2n-2

⇒an = 2n-2

→a1 = 2(1)-2

→a1 = 0

⇒a2 = 2(2)-2

→a2 = 4-2

→a2 = 2

⇒a3 = 2(3)-2

→a3 = 6-2

→a3 = 4

⇒a4 = 2(4)-2

→a4 = 6

⇒a5 = 2(5)-2

→a5 = 8

∴the first five terms are 0,2,4,6,8

c) 3n +4

⇒a1 = 3(1)+4

→a1 = 7

⇒a2 = 3(2)+4

→a2 = 10

⇒a3 = 3(3)+4

→a3 = 13

⇒a4 = 3(4) + 4

→a4 = 16

⇒a5 = 3(5)+4

→a5 = 19

∴the first 5 terms are 7,10,13,16,19

d) n (n+1)

⇒a1 = 1(1+1)

→a1 = 2

⇒a2 = 2(2+1)

→a2 = 6

⇒a3 = 3(3+1)

→a3 = 12

⇒a4 = 4(4+1)

→a4 = 20

⇒a5 = 5(5+1)

→a5 = 30

∴the first 5 terms are 2,6,12,20,30

e) n²

⇒ a1 = 1²

→a1 = 1

⇒a2 = 2²

→a2 = 4

⇒a3 = 3²

→a3 = 9

⇒a4 = 4²

→a4 = 16

⇒a5 = 5²

→a5 = 25

∴the first 5 terms are 1,4,9,16,25

explanation:

⇒to find the first 5 terms, substitute the value of n which is the number of terms