How do you calculate even or odd functions?

[Aka]

I know an even function satisfies f(x)=f(-x) for all values of x in its domain. An odd function satisfies f(-x)=-f(x) for all the values of x in the domain. But, how do you calculate this if you have an equation?
ex. f(x)=-2x+1

 

[Libertine]

I know an even function satisfies f(x)=f(-x) for all values of x in its domain. An odd function satisfies f(-x)=-f(x) for all the values of x in the domain. But, how do you calculate this if you have an equation?
ex. f(x)=-2x+1

You insert the value of x and see if it matches, e.g.
f(x) = -2x+1
f(-x) = -2(-x) + 1
= 2x+1
so it isn't even...

Do a similar thing to test if it is odd (be careful with the brackets)

 

[Aka]

^ ok, thanks