Gif 2
Focus of a HyperbolaGif 3
How to Make a HyperbolaGif 4
Parabola as LocusGif 5
Parabola as ConstructionGif 6
Case I : When $|a| > 1 $
The larger the $ |a|$ is, the more the graphs narrows.
Case II : When $|a| < 1 $
The larger the $ |a|$ is, the more narrow the parabola is. Or, another way to think of it, the closer that the value of $a$ gets to zero, the wider the parabola becomes.