Question

Tentukan empat suku pertama suatu barisan yg suku ke-n nya dinyatakan dgn
(n-1)(2n+1) =

Answer 1

U1 = (1-1)(2x1+1)
U1 = 0 x 3
U1 = 0
U2 = 1 x 5
U2 = 5
U3 = 2 x 7
U3 = 14
U4 = 3 x 9
U4 = 27

Jadi U1 = 0 ; U2 = 5 ; U3 = 14 ; U4 = 27

Answer 2

Un = (n - 1)(2n + 1)
U1 = (1 - 1)(2 * 1 + 1) = 0 * 3 = 0
U2 = (2 - 1)(2 * 2 + 1) = 1 * 5 = 5
U3 = (3 - 1)(2 * 3 + 1) = 2 * 7 = 14
U4 = (4 - 1)(2 * 4 + 1) = 3 * 9 = 27

= 0, 5, 14, 27