Exponential function is one of the important basic elementary functions. Generally speaking, the function of y = a x (a is constant and a >；; 0, a≠ 1) is called exponential function, and the definition domain of the function is R. Note that in the definition expression of exponential function, the coefficient before a x must be the number 1, and the independent variable X must be in the exponential position, and it cannot be other expressions of X, otherwise it is not an exponential function.

Functional image

(1) From the point where the exponential function y = a x intersects the straight line x= 1 (1), it can be known that on the right side of the y axis, the base corresponding to the image changes from bottom to top.

(2) From the point (-1, 1/a) where the exponential function y = a x intersects with the straight line x=- 1, it can be seen that on the left side of the Y axis, the corresponding base of the image changes from large to small.