Question

Write the first 3 numbers of the sequence. an=a1*r^n-1 an=2*(3)^n-1

Answer 1

2, 6, 18

Explanation:

`a_n=2(3)^(n-1)\\\\\text{Put n = 1, n = 2 and n = 3 to the equation:}\\\\a_1=2(3)^(1-1)=2(3)^0=2(1)=2\\\\a_2=2(3)^(2-1)=2(3)^1=2(3)=6\\\\a_3=2(3)^(3-1)=2(3)^2=2(9)=18`