For the function y = f(x) = x^5 + 2x^3 + 3x + 1

How do I go about expressing x in terms of y?

Thanks.

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- Aug 18th 2009, 04:24 AMtashboExpressing x in terms of y
For the function y = f(x) = x^5 + 2x^3 + 3x + 1

How do I go about expressing x in terms of y?

Thanks. - Aug 18th 2009, 04:58 AMGrandad
Hello tashbo

Welcome to Math Help Forum!Without wishing to sound frivolous: with great difficulty! The answer is that you may be able to find a value (or possibly several values) of $\displaystyle x$, given a specific value of $\displaystyle y$, but you won't be able to find a formula that will do it for*any*value of $\displaystyle y$. This is because there's no straightforward way of solving an equation like this - with terms in $\displaystyle x^5,\, x^3$ and $\displaystyle x$.

Grandad - Aug 18th 2009, 05:20 AMtashbo
Thanks for that- I think that maybe I am misunderstanding therefore what I need to do!

- Aug 18th 2009, 06:14 AMtashboInverse Funtion Rule
how do I find the inverse of f^-1 for a polynomial function such as

y = f(x) = x^5 + 2x^3 + 3x + 1 in order then to go on to use the Inverse Function Rule for some given values? - Aug 18th 2009, 06:37 AMmr fantastic
This is essentially the same question that you've already asked. The reply given by Grandad still applies.

**Post the original question!**What I've highlighted in red implies crucial missing information - it's almost certain that you don't have to find the rule for the inverse function. - Aug 18th 2009, 07:23 AMtashbo
It seems that I have repeated myself as I am having difficulty understanding the question I am trying to answer - it was not intentional and I apologise.

Quote:

Originally Posted by**Mr Fantastic**

- Aug 18th 2009, 07:29 AMmr fantastic