Re: How to find out the x value?

Roger Stafford — Fri, 18 Jan 2008 05:10:03 -0500

"Il Yoon" <matlab_newsgroup@mathworks.com> wrote in message <fmpbh1
$2qa$1@fred.mathworks.com>...
> Hello all,
>
> Here is a polynomial, y=3x^3+2x^2-5x-3
>
> If I want to know the x value, when y is 20, how can I find
> it? Is there any simple way?
>
> Thank you in advance.
>
> Il Yoon
---------
y = 20;
x = roots([3,2,-5,-3-y]);

There will be three roots.

Roger Stafford

How to find out the x value?

Il Yoon — Fri, 18 Jan 2008 04:56:01 -0500

Hello all,

Here is a polynomial, y=3x^3+2x^2-5x-3

If I want to know the x value, when y is 20, how can I find
it? Is there any simple way?

Thank you in advance.

Il Yoon

MATLAB Central Newsreader - How to find out the x value?

Re: How to find out the x value?

How to find out the x value?