Question

Tentukan unsur yang diminta pada deret geometri U4= 1/9 ; a = -3 ; r =....???

Answer 1

U4=ar³
1/9=-3r³
-27r³=1
r³=1/-27
r=1/-3

Answer 2

U4 = 1/9
ar^3 = 1/9
-3 . r^3 = 1/9
r^3 = -1/27
r^3 = (-1/3)^3
r = -1/3