Question

Which formula can be used to find the nth term in a geometric sequence where a1=3 and r=2 ?

Answer 1

1st term =a₁ = 3,  r=2

1st a₁   = 3 x 2⁰
2nd a₂  = 3 x 2¹
3rd a₃  =  3 x 2²
4th a₄   = 3 x 2³
5th a₅   = 3 x 2⁴
.......................
.......................
nth : a(n) = 3 x 2⁽ⁿ-¹)
Note when that the subscript of a is the same as the exponent mines 1

Answer 2

A(n)=a(1)*r^(n-1)

a(n)=3*2^(n-1)

Hope I don't mess up for your sake.