Cal 2 ratio test where is my mistake

[Jac8897]

cal 2 ratio test "where is my mistake"

Homework Statement

I attached a pic
I solved the problem but i get 4^1 and the book says 4^2 I don't know why?

Homework Equations

http://img690.imageshack.us/img690/1518/problem15.jpg

The Attempt at a Solution

 

[lanedance]

when you sub in for n -> n+1 in exponent of the 4 it should be

\frac{4^{(2n+1)}}{4^{(2(n+1)+1)}}

 

[Jac8897]

when you sub in for n -> n+1 in exponent of the 4 it should be

\frac{4^{(2n+1)}}{4^{(2(n+1)+1)}}

got it

thank you