According to different functions, laws are different. Because the proportional function is a linear function, the increase and decrease of x and y are synchronous, and the function image remains unchanged. The inverse proportional function x increases, y decreases, x decreases and y increases, so its image expands, the value of x decreases, and the value of x increases.

Quadratic function y=ax? +bx+c image magnification x is positively correlated with y.

In addition, trigonometric function, logarithmic function, exponential function and other issues are complicated and I don't want to study them.