If #\blue c>0#, the equation has two solutions:

\[\begin{array}{rcl}
x^2 &=&\blue c \\
&\text{gives}&\\
x = \sqrt{\blue c} &\lor& x = -\sqrt{\blue c}
\end{array}\]

The symbol #\lor# means "or".

If #\blue c=0#, the equation has one solution:

\[\begin{array}{rcl}
x^2 &=& \blue c \\
&\text{gives}&\\
x &=&0
\end{array}\]

If #\blue c<0#, the equation has no solutions:

\[\begin{array}{rcl}
x^2 &=&\blue c
\end{array}\]

The graph on the right demonstrates that the graphs #y=\blue c# and #y=x^2# never intersect as long as #\blue c<0#.