1. Positive proportion function 2. Inverse proportion function 3. Primary function 4. How to find the domain of definition of quadratic function? Is it based on the solution set, or what?

1. Positive proportion function 2. Inverse proportion function 3. Primary function 4. How to find the domain of definition of quadratic function? Is it based on the solution set, or what?

The solution of the domain of definition of all functions is just to see the following points:
1. The denominator is not equal to 0
2. The formula in the root sign is not less than 0
3. Some special functions have their own domain of definition, such as the trigonometric function TaNx, where x ≠ K π + π / 2
According to these points, the formula can be solved