Question

PLEASE ANSWER THIS

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

Solution:

(a) Given: aₙ = 5n

a₁ = 5×1 = 5

a₂ = 5×2 = 10

a₃ = 5×3 = 15

a₄ = 5×4 = 20

a₅ = 5×5 = 25

So, the first five terms of 5n are 5,10,15,20 and 25.

(b) Given: aₙ = 2n-2

a₁ = (2×1)-2 = 0

a₂ =(2×2)-2 = 2

a₃ = (2×3)-2 = 4

a₄ = (2×4)-2 = 6

a₅ = (2×5)-2 = 8

So, the first five terms of 2n-2 are 0,2,4,6 and 8.

(c) Given: aₙ = 3n+4

a₁ = (3×1)+4 = 7

a₂ = (3×2)+4 = 10

a₃ = (3×3)+4 = 13

a₄ = (3×4)+4 = 16

a₅ = (3×5)+4 = 19

So, the first five terms of 3n+4 are 7,10,13,16 and 19.

(d) Given: aₙ = n(n+1) = n²+n

a₁ = 1²+1 = 2

a₂ = 2²+2 = 6

a₃ = 3²+3 = 12

a₄ = 4²+4 = 20

a₅ = 5²+5 = 30

So, the first five terms of n(n+1) are 2,6,12,20 and 30.

(e) Given: aₙ = n²

a₁ = 1² = 1

a₂ = 2² = 4

a₃ = 3² = 9

a₄ = 4² = 16

a₅ = 5² = 25

So, the first five terms of n² are 1,4,9,16 and 25.