Exponential function y=ax (a > 0 and a≠ 1), logarithmic function y=logax (a > 0 and a≠ 1), exponential function y=ax and logarithmic function y=logax are reciprocal functions.
Extended data
Y=2x and x=logay are actually two different expressions of the corresponding relationship between X and Y, which are essentially the same. For example, when x=2, you can get y=4 no matter which expression you use. But the status of x and y has changed. Y is an exponential function of X, and X is a logarithmic function of Y. ..
According to the custom, if we use X as the independent variable of the function and Y as the dependent variable, then the inverse function y=2x(x∈R) x=logay(y∈(0, +∞)) of the exponential function becomes y=logax(x∈(0, +∞)). Therefore, to find the inverse function of y=2x, we can switch x and y to get x=2y, and then solve y=log2x.
Generally, the inverse function of the function y=f(x) is expressed as y=f- 1(x).
Therefore, when finding the inverse function of the function y=f(x) in the future, you can do this:
Step 1, exchange x and y in y=f(x) to get x = f (y);
Step 2, get y from x=f(y).