Find the first four terms of the sequence defined by:
Un = 4Un-1, U1 = 2
I know the steps, but i dont know what U2, U3, and U4. I think i someone explained that to me i will be able to do it.
The way that is written then it is saying that $\displaystyle Un = 4Un-1$.
So $\displaystyle U1 = 4U1-1$
$\displaystyle 2 = 4x2 - 1$.
If the formula you have means that the next one in the squence is equal to $\displaystyle 4Un-1$
Then you would have $\displaystyle 2, (4x2)-1, (4x((4x2)-1)-1$.
Obviously you would simplify the above answer
No. The OP means Un = 4U_(n-1) or, even better, $\displaystyle Un = 4U_{n-1}$.
You will need to better learn how to interpret poor formatting (which is why users are encouraged to learn basic latex).
To the OP:
Nope, it's not exactly how you wrote it. Please take the time to learn some basic latex so that you can format equations more clearly next time. See here: http://www.mathhelpforum.com/math-help/latex-help/