Question

Tentukan enam suku pertama suatu barisan bilangan, bila rumus suki ke-n barisannya adalah:
a.Un=n(5-2n)
b.Un=n(n+3)
c.Un=2n(n-1)

Answer 1

A. 3, 2, -3, -12, -25, -42
b.4, 10, 18, 28, 40, 54
c. 2, 4, 12, 24, 40, 60

Answer 2

1).

U₆ = 6 ( 5 - 2(6) )
U₆ = 6 ( 5 - 12 )
U₆ = -42

2).

U₆ = 6 ( 6 + 3 )
U₆ = 54

3).

U₆ = 2n ( n - 1 )
U₆ = 2(6) ( 6 - 1 )
U₆ = 60