Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 26 Sep 2016, 03:57

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# The two roots r1 and r2 of the quadratic equation 5x^2 - px

Author Message
Senior Manager
Joined: 30 Aug 2003
Posts: 329
Location: BACARDIVILLE
Followers: 1

Kudos [?]: 18 [0], given: 0

The two roots r1 and r2 of the quadratic equation 5x^2 - px [#permalink]

### Show Tags

29 Jan 2004, 14:05
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

The two roots r1 and r2 of the quadratic equation 5x^2 - px + 1 = 0
are such that |r1 - r2| = 1, find 'p'.

a. 2sqrt3
b. -2sqrt3
c. both (a) and (b)
d. 3sqrt5
e. Too busy checking out the hot chick
_________________

Pls include reasoning along with all answer posts.
****GMAT Loco****
Este examen me conduce jodiendo loco

SVP
Joined: 30 Oct 2003
Posts: 1793
Location: NewJersey USA
Followers: 5

Kudos [?]: 90 [0], given: 0

### Show Tags

29 Jan 2004, 14:35
D ?

r1 = ( p+sqrt( p^2-20 ) ) / 10
r2 = ( p-sqrt( p^2-20 ) ) / 10
|r1-r2| = sqrt( p^2-20 )/5 = 1
p^2 = 45
p = 3sqrt(5)
Senior Manager
Joined: 30 Aug 2003
Posts: 329
Location: BACARDIVILLE
Followers: 1

Kudos [?]: 18 [0], given: 0

### Show Tags

29 Jan 2004, 14:43
Good.

Also, note that the difference between roots is equal to: sqrt of the discriminat over 'a'.
Also note that if a root exceeds the other root by a certain amount 'k', then (a^2)(k^2) = b^2 - 4ac
_________________

Pls include reasoning along with all answer posts.
****GMAT Loco****
Este examen me conduce jodiendo loco

Display posts from previous: Sort by