Ask the Math Emperor to tell me something about odd function X=0. . . Thank you.

If odd function decides that the domain of f(x) is R, then f(0)=0. If the topic tells you that the function f(x) is odd function and there is a letter in the function formula, you need to observe whether the domain is R. If so, you can find this letter by substituting f(0)=0, but if you want to check it, you can bring in the letter to verify that f(x)=-f(-x). If you can't solve other numbers in the domain, such as plus or minus 1 plus or minus 2, or make f(x)=f-(-x).