(1) defines the function in the form of y=xα as a power function, where α is a constant, and only studies the case that α is a rational number in middle school.

2. Exponential function and logarithmic function

(1) definition

Exponential function, y = ax (a > 0, and a≠ 1), pay attention to the difference with power function.

The logarithmic function y = logax (a > 0 and a ≠ 1).

Exponential function y=ax and logarithmic function y=logax are reciprocal functions.

(2) The images and properties of exponential function y = ax (a > 0, and a≠ 1) and logarithmic function y = logax (a > 0 and a≠ 1) are shown in table 1-2.

(3) Exponential equation and logarithmic equation

Exponential equation and logarithmic equation belong to transcendental equation. In middle school, just solve some simple and special types of exponential equations and logarithmic equations. The basic idea is to turn them into algebraic equations to solve. See table 1-3 for the basic types and solutions.