# Functions problem

• Aug 5th 2011, 02:15 AM
jgv115
Functions problem
See the attachments.

This question was a question on this year's AMC. I was just wondering how to do it.

It should be done without a calculator :)
• Aug 5th 2011, 02:35 AM
Ackbeet
Re: Functions problem
You're going to have to "build up" your answer, recursively. These functions are defined recursively. I would try this: construct a table with columns x, f(x), g(x), and h(x). Then just start marching across the rows until you have finished out the x = 4 row. The last number in the h column will be your answer.
• Aug 5th 2011, 04:13 AM
jgv115
Re: Functions problem
Wow that makes things much simpler!

I got 125, is that correct?
• Aug 5th 2011, 06:08 AM
Ackbeet
Re: Functions problem
Quote:

Originally Posted by jgv115
Wow that makes things much simpler!

I got 125, is that correct?

That's what I get.
• Aug 5th 2011, 06:21 AM
jgv115
Re: Functions problem
Yay! If only I knew that on the actually exam. Haha!

Anyway, thanks a lot Ackbeet!
• Aug 5th 2011, 06:34 AM
Ackbeet
Re: Functions problem
You're very welcome. Have a good one!