# Homework Help: Odd ball Poly-Nominal Question

1. Aug 3, 2009

### Venito

1. The problem statement, all variables and given/known data
A. Expand the function, f[x]= [1+x] to the power three, [What I mean is is the [1+x] is cubed. in increasing powers of x, and sate whether or not the function is a poly-nominal, giving reasons.

B. Plot graph f[x]

C. On the same axes plot the functions, g[x] which contain the first two terms of the expansion, and h[x] which contain the first three terms of the expansion.

3. The attempt at a solution

I have tried question A.

f[x]=[1+x]Cubed.
=[1+x][1+x][1+x]
=x cubed + 3x squared +3x + 1.

This question is a poly nominal.

But that is as far as I can go. I don't know if I am right or wrong and what to do with this question.

2. Aug 3, 2009

### songoku

Hi Venito

Yes, you're right
f(x) = x^3 + 3x^2 + 3x + 1, but the question wants you to do it in increasing powers of x, so f(x) = 1 + 3x + 3x^2 + x^3

I think this will be helpful :http://en.wikipedia.org/wiki/Polynomial

For (b) : find the intersection with the axis and find also the stationary point to sketch the graph

For (c) : sketch g(x) = 1 + 3x and sketch h(x) = 1 + 3x + 3x^2

3. Aug 3, 2009

### Venito

Right that makes sense. With the changes made I should come out.

Thanks.

4. Aug 4, 2009

### songoku

You're welcome ^^