Problem:
Explore the graph of the function
f(x) = x4 - 3 x2
for values of x between -2 and 2 to view geometrically
that the graph of this function is symmetric with respect to the y-axis.
Visualization:
In the following LiveMath Notebook, you can view the graph of y = f(x)
(blue graph) and a straight line segment (red graph) between the points (a, f(a)) (green point) and
(-a, f(-a)) (yellow point). Note that this line segment
appears to be perpendicular to and is bisected by the y-axis. This implies
that the points (a, f(a)) and (-a, f(-a)) are symmetric
with respect to the y-axis.
Note that as you change the value of a, the points (a, f(a)) and (-a, f(-a)) still appear to be symmetric with respect to the
y-axis.
You can change the function in the notebook above. Try
- x4- 9x2
[You will need to zoom out to see the entire line segment. To zoom out, click on the 'rocket ship' on the upper left-hand corner of the graph.]
- x6- 9x2
- x4- 9x3
- x6- 9x4
[To change a coefficent in the definition of f(x) in the notebook above, highlight
the coefficent with the mouse and then type in the new coefficient.]