[tex]\bf \begin{array}{llccll}
y=&1x^2&-6x&+9\\
&\uparrow &\uparrow &\uparrow \\
&a&b&c
\end{array}\qquad discriminant\implies b^2-4ac[/tex]
so... what does that give you for the discriminant?
if it's a negative value, no solutions
if it's a positive value, two solutions
if it's 0, one solution
