View Single Post
thornluke
thornluke is offline
#1
Dec10-11, 01:18 AM
P: 37
1. The problem statement, all variables and given/known data
The equation kx2 - 3x + (k+2) = 0 has two distinct real roots. Find the set of possible values of k.


2. Relevant equations
Since the equation has two distinct real roots, b2 - 4ac > 0

3. The attempt at a solution
b2-4ac>0
9-4(k+2)(k)>0
9-4(k2+2k) >0
9-4k2-8k>0
= -4k2-8k+9>0
Multiply both sides by -1,
4k2+8k-9>0
(4k-3)(k+3)>0

-3<k<3/4

However the answer is -2.46<k<0.458
I'm lost, help please!
Phys.Org News Partner Science news on Phys.org
Going nuts? Turkey looks to pistachios to heat new eco-city
Space-tested fluid flow concept advances infectious disease diagnoses
SpaceX launches supplies to space station (Update)