Power function: a function in the form of y = x a (a is constant), that is, a function with x as independent variable and a as dependent variable, where a is constant is called a power function. The image of power function shows different appearances with different values of a, which needs specific analysis. The following are several common power function images.

Exponential function: the general form is y = a x (a > 0 and ≠ 1)? (x∈R)。 ? This is one of the basic functions. Where a is a constant and x is a variable.

Linear function: also known as linear function, it can be represented by a straight line on the X and Y axes. When the value of one variable in a linear function is determined, the value of another variable can be determined by a linear equation of one variable. For example, y=ax+b, where a and b are constants and x is a variable.

Quadratic function: refers to a polynomial function with the highest unknown degree of quadratic. The quadratic function can be expressed as f (x) = ax 2+bx+c (a is not 0). Its image is a parabola, and its principal axis is parallel to the Y axis.

Logarithmic function: generally speaking, the function y=log(a)X, (where a is a constant and a >；; 0 and a is not equal to 1) is called logarithmic function, which is actually the inverse of exponential function. That is, exponential function and logarithmic function are symmetric about the straight line y = X.

The latter four function images are in the teaching materials, which can be referenced or searched online.