We know that if a function is even then the graph of the function is symmetrical about y-axis.
Look at the first function, it is symmetrical about y-axis, henve it is even,
if a function is odd then the graph of the function is symmetrical about origin
Look at the second function, it is symmetrical about origin, henve it is odd,
And the third function is neither symmetrical about y-axis nor symmetrical about origin and so it neither odd nor even.
