# Thread: odd or even function

1. ## odd or even function

how do i show f(x)=x^2 is even

2. Originally Posted by nothingness22
how do i show f(x)=x^2 is even
$f(x)$ is even if $f(x)=f(-x)$ for every x in the domain of f.

3. Even functions are always symmetric to the y axis.
Odd functions are always symmetric to x axis.

So, f(x) = x^2 would be even, because it is symmetric to the y axis. (see pic)
Additionally, the 2 in x^2 is even, which is a big hint right away.

4. Originally Posted by nothingness22
how do i show f(x)=x^2 is even
A great way is to simply make a table of values.

X Y
-4 16
-3 9
-2 4
-1 1
0 0
1 1
2 4
3 9
4 16