Enlarging or reducing parabolas
If you enlarge or reduce a parabola you make it steeper or flatter and there are four elements you need to remember.
y=2x2 - Doubles the distance from the x axis.
y=12x2 - Halves the distance from the x axis.
y=(2x)2 - Halves the distance from the y axis.
y=(12x)2 - Doubles the distance from the y axis.
We can remember this by using the following chart:
Note also that
y=3x2 - Triples the distance from the x axis.
y=13x2 - Thirds the distance from the x axis.
y=(3x)2 - Thirds the distance from the y axis.
y=(13x)2 - Triples the distance from the y axis.
y=x2
y=x2 should be plotted as:
x=4 | y=42 | =16 | |
x=3 | y=32 | =9 | |
x=2 | y=22 | =4 | |
x=1 | y=12 | =1 | |
x=0 | y=02 | =0 | |
x=-1 | y=(-1)2 | =1 | |
x=-2 | y=(-2)2 | =4 | |
x=-3 | y=(-3)2 | =9 | |
x=-4 | y=(-4)2 | =16 |



