Question

Write an explicit formula for a^n , the nth term of the sequence 18,−6,2,

Answer 1

Explanation:

`a_1=18\\\\a_2=-6=(18)/(-3) \\\\a_3=2=(-6)/(-3)=18*((1)/(-3) )^2\\\\a_4=18*((1)/(-3) )^3\\\\...\\a_n=18*((1)/(-3) )^(n-1)\\\\`

The sequence is a GP with first term is 18 and ratio equal -1/3