Tentukan suku ke 8 dan suku ke – n dari barisan aritmatika 2,5/5 3,7/5
Jawaban:
barisan
2, 5/2, 3, 7/2
a = 2
b = 5/2 – 2 = 5/2 – 4/2 = 1/2
b = 1/2
U8 = a + 7b
U8 = 2 + 7(1/2)
U8 = 2 + 7/2 = 4/2 + 7/2
U8 = 11/2
Un = a + (n – 1)b
Un = 2 + (n – 1) x 1/2
Un = 2 + (1/2)n – 1/2
Un = (1/2)n + 3/2
Un = 1/2(n + 3)
Jawaban:
maap klo slah
Penjelasan dengan langkah-langkah:
barisan
2, 5/2, 3, 7/2
a = 2
b = 5/2 – 2 = 5/2 – 4/2 = 1/2
b = 1/2
U8 = a + 7b
U8 = 2 + 7(1/2)
U8 = 2 + 7/2 = 4/2 + 7/2
U8 = 11/2
Un = a + (n – 1)b
Un = 2 + (n – 1) x 1/2
Un = 2 + (1/2)n – 1/2
Un = (1/2)n + 3/2
Un = 1/2(n + 3)