Question

How can you use a point on the graph of f –1(x) = 9x to determine a point on the graph of f(x) = log9x?

Answer 1

Answer: switch x and y coordinates

Explanation:

Answer 2

Whenever you can invert a function, you have that the graphs of
`f(x)` and its inverse
`f^(-1)(x)` are reflected with respect to the line
`y=x`

So, given any point on the graph of
`f^(-1)(x)`, you can simply swap its coordinates to get the correspondent point on the original function
`f(x)`

As an example, all exponential functions pass through the point
`(0,1)`, while all the logarithmic functions pass through the point
`(1,0)`