+476 Enter a recursive rule for the geometric sequence.
2, 6, 18, 54, …
a1=____ ; an=____
The one and the n are both subscript facing down so like an exponent just a lower exponent.
+128474 a1 = 2 = 1st term
We need to find the common ratio from one term to the next
r = common ratio = subsequent term / previous term = 6/2 = 3
To find any term, an.....we have
an = a1 * r(n - 1) = 2(3)rn-1 where n is the nth term
So....for example....if we wanted the 4th term...we have
2 (3) 4-1 = 2(3)3 = 2*27 = 54 .....as expected !!!
