Formula bilangan ganjil positif.docx
- 1. Formula bilangan ganjil positif:
1 + 3 + 5 + 7 + .... + (2n – 1)
(2n – 1) + (2n – 3) + (2n – 5) + (2n – 7) + ...... + 1
2n + 2n + 2n + 2n + ........ + 2n =
𝑛
2
. 2n = n . n = n2
1 + 3 + 5 + 7 + .... + 85 = ?
85 = 2n – 1
2n = 86
n = 43
Jadi, 1 + 3 + 5 + 7 + .... + 85 = n2
= 432
= 1849