Is odd function symmetric about origin? Even function symmetric about y axis? How do you judge them? Can you give me an example. What is f (- x) = - f (x) What is f (x) = f (- x) Why don't you two say the same thing? It's hard to understand

Is odd function symmetric about origin? Even function symmetric about y axis? How do you judge them? Can you give me an example. What is f (- x) = - f (x) What is f (x) = f (- x) Why don't you two say the same thing? It's hard to understand

Odd function, judge f (x) = - f (- x)
Even function, judge f (x) = f (- x)