# show that the function is not 1-1

• April 24th 2010, 07:29 PM
tn11631
show that the function is not 1-1
Show that the function f(x)=2 $x^3$+3 $x^2$+17 is not 1-1 on the interval [-1,1].
• April 24th 2010, 07:34 PM
It has a minimum at x=0...
• April 24th 2010, 07:50 PM
alice8675309
Quote:

It has a minimum at x=0...

I'm sorry I made a mistake its x^3-3x^2+17. I'm guessing it would be the same? But isn't the minimum at x=1?
• April 24th 2010, 08:03 PM
Yes, same idea, that one still has an extremum in the interior of [-1,1] (at x=0).

edit: wait, who asked this question??
• April 24th 2010, 08:04 PM
tn11631
Quote:

Originally Posted by alice8675309
I'm sorry I made a mistake its x^3-3x^2+17. I'm guessing it would be the same? But isn't the minimum at x=1?

Hm that's pretty strage since I posted this question. Lol but what I have originally posted is the question. Weird.
• April 24th 2010, 08:10 PM