Andrew M. answered 07/04/15
Tutor
New to Wyzant
Mathematics - Algebra a Specialty / F.I.T. Grad - B.S. w/Honors
From ax2+ bx + c which is a quadratic equation graphing to a parabola
Solve for the determinant , the part under the square root... b2-4ac
from the quadratic equation x =[ -b ± √(b2-4ac)]/2a
if b2-4ac is positive we have 2 real roots
if b2-4ac = 0 we have 1 real root
if b2-4ac is negative we have 2 imaginary roots which are complex conjugates
In this case we have x2-12x+ 36
a = 1 b = -12 c =36
b2-4ac = (-12)2-4(1)36 = 144 - 144 = 0
Since the determinant = 0 we will have only one real root (x=6 as Maria stated)