Question

Suku ke-10 dari barisan bilangan 4, 12, 26, 46... adalah...

Barisan aritmatika bertingkat
Un=an²+bn+c

Answer 1

A + b + c =4, 12, 26, 46
3a + b= 8, 14, 20
2a= 6, 6

*2a = 6
a=6/2=3

*3a+b= 8
3.3+b=8
9+b=8
b=8-9= -1

*a+b+c=4
3-1+ c=4
c=4-2=2

#Un=an^+bn+c
U10=(3×10)^ + (-1×10) + 2
= 900 -10 +2
= 892