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Oliver
07-11-2013, 05:04 PM
How can we find the value of the parameter m if the following equation

x^2-(m+3)x+(m+6)=0

has one real root.

Thanks!!:D

kadence
07-11-2013, 05:09 PM
SAT math question about Quadratic Equations

The discriminant of the quadratic in terms of m is

\Delta=b^2-4ac=(m+3)^2-4(m+6)=m^2+2m-15=(m+5)(m-3)

For the quadratic equation to have one real solution, the discriminant \Delta must be equal to zero

Therefore:

\Delta=0

(m+5)(m-3)=0

m=-5 \or\ m=3

Hope these help!!:D:D

Oliver
07-11-2013, 05:10 PM
Thank you Kadence!!