what graphs are even or odd?

in what grade do you learn this....

Hello guys I got the answer. I dont need any help from this question. Thank you. Im in 9 grade

The first one is even becasue it is symmetrical about the y axis. That is f(x)=f(-x)

The second one is odd because it has 180 degree roational symmetry about (0,0)

i.e. f(-x)=-f(x)

The third one is neither.