by baz90@[EMAIL PROTECTED]
Mar 10, 2008 at 04:14 AM
On Mar 10, 9:54 pm, William Elliot <ma...@[EMAIL PROTECTED]
> wrote:
> On Mon, 10 Mar 2008 ba...@[EMAIL PROTECTED]
wrote:
>
> > Hello; a simple question if someone could please show how to do it; a
> > cube has side length 15cm. What is the max. possible % error in the
> > volume? thanks if you can help. baz
>
> Let x be the side of the cube and dx a small error in x.
>
> Then V(x) = x^3 and V(x + dx) = x^3 + 3x^2 dx + 3x dx^2 + dx^3.
>
> The dx^2 and dx^3 terms can usually be ignored when dx is small.
>
> For example. x = 1, dx = 1/10 or dx = 1/20.
>
> The usual calculus approximation for error is
> V(x + dx) = V'(x) + 3x^2 dx
>
> which if you notice is the same result gotten by ignoring
> dx^2 and dx^3 for being too small to be notice.
the question is from a pre-calculus unit on measurement and error
