# What is the discriminant of y=x^2-6x+9 and what does that mean?

Jul 26, 2015

$y = {x}^{2} - 6 x + 9$
$D = {b}^{2} - 4 a c = 36 - 36 = 0.$ This means there is a double root
In fact, this function y is in the form $y = {\left(x - 3\right)}^{2.}$