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Topic: Help Needed in math
Replies: 25   Last Post: May 2, 2014 6:01 PM

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 William Elliot Posts: 2,637 Registered: 1/8/12
Re: Help Needed in math
Posted: Apr 29, 2014 5:23 AM

On Mon, 28 Apr 2014, Peter Percival wrote:
> punisher wrote:
>

> > Find the largest values of the integer a for which ax^2-5x-3 is
> > negative for all values of x.

> Minus three.

ax^2 - 5x - 3
(5 +- sqr(25 + 12a)/2a
25 + 12a < 0; a < -25/12

ax^2 - 5x - 3 < -25x^2 / 12 - 5x - 3 < 0 ?
-25x^2 - 60x - 36 = -(5x + 6)^2 <= 0

Date Subject Author
4/28/14 punisher
4/28/14 quasi
4/29/14 Peter Percival
4/29/14 Karl-Olav Nyberg
4/28/14 Peter Percival
4/29/14 William Elliot
4/29/14 Peter Percival
4/29/14 Karl-Olav Nyberg
4/29/14 Karl-Olav Nyberg
4/29/14 Karl-Olav Nyberg
4/29/14 Karl-Olav Nyberg
4/29/14 William Elliot
4/30/14 Karl-Olav Nyberg
4/30/14 William Elliot
4/30/14 Karl-Olav Nyberg
4/30/14 William Elliot
5/1/14 Karl-Olav Nyberg
5/1/14 William Elliot
5/1/14 quasi
5/2/14 William Elliot
5/2/14 quasi
5/2/14 William Elliot
5/2/14 snmpprotocol@gmail.com
5/2/14 quasi
5/2/14 Karl-Olav Nyberg
5/2/14 quasi