Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: 1.94 - What math PhDs say about limit theory in calculus.
Replies: 9   Last Post: Jul 11, 2014 12:53 PM

 Messages: [ Previous | Next ]
 johngabriel2009@gmail.com Posts: 354 Registered: 5/25/14
Re: 1.94 - What math PhDs say about limit theory in calculus.
Posted: Jul 11, 2014 1:45 AM

On Thursday, July 10, 2014 9:04:26 PM UTC+2, Dan Christensen wrote:
> On Thursday, July 10, 2014 1:50:45 PM UTC-4, John Gabriel wrote:
>

> > 1. If f(x)=x, then f'(0)=1.
>
> >
>
> >
>
> >
>
> > TRUE
>
> >
>
> >
>
> >
>
> > 2. If f(x)=x^3, then f'(0)=0.
>
> >
>
> >
>
> >
>
> > FALSE, because there is no tangent line at x=0. It does not matter that you obtain f'(0)=0 by plugging 0 into 3x^2.
>
> >
>
>
>
> There is a tangent line at x=0, just like there is one for f(x)=x.
>
>
>
> I really think you will have to join Prof. Ullrich's remedial class.

Hey stupid, if f(x)=(x-1)^(1/3) + 2 is the position function, then what is the speed at x = 1?