00:01
So in this problem, you're told that you need to assume that f is a one -to -one function.
00:04
And what a one -to -one function is means that it passes both the vertical and horizontal line test.
00:10
So its inverse is a function as well.
00:12
So in part a, you're told that for some function, f, the f of 9 is equal to 11.
00:18
What you want to find is f inverse of 11.
00:24
So that's what we're looking for.
00:26
Well, remember, to find the inverse of a function, you simply switch the order pairs.
00:31
F of 9 equals to 11, remember, 9 would be your input and 11 is your output.
00:35
So the ordered pair would be 9 .11.
00:38
So when you take the inverse of that, all you're doing is you're switching your x and y values, which means the inverse of that point would be 119.
00:46
So now we can go back and answer the question...