Question 155038: for what value(s) of p does the equation x^2+px+1=0 have no real solutions, and two real solutions.
Answer by Fombitz(32388)   (Show Source):
You can put this solution on YOUR website! For this discussion, we'll use the discriminant.
For the general quadratic equation,
the discriminant is
.
.
If  then you have two distinct real roots.
If  , you have a double root, one real root occurring twice
If  , you have two complex roots, that are complex conjugates.
For no real (complex) solutions,
Valid interval: ( )
.
.
.
.
For two real solutions,
 and 
Valid interval:( , ]U[ , )
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