Wdym mean across the origin? Note that sqrt() always returns a positive value so a negative in front of the square root means that y will always be below or equal to zero. If you are asking about the reflection in the y-axis, the negative sign in front if the x term does reflect the curve about the y-axis. Think about like this: you translate the curve 4 unites to the left, THEN you reflect the curve about the x axis, due to the negative sign. Of course the negative sign in front of the sqrt() reflects the curve in the x-axis. This will result in the curve you drew above, ignoring the dotted lines