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# c3 - functions Watch

1. Dear Helper,
I want to know why the author in this example chose (x) instead of x - 3 or x+3

I have attached the picture

thank
2. Since the functions are inverses and so are reflections and mirror images of each other in the y=x line, if they intersect at any point, they will intersect in the line y=x. So you can just let f(x)=x and solve or you could even let f^-1(x)=x and then solve.
3. (Original post by B_9710)
Since the functions are inverses and so are reflections and mirror images of each other in the y=x line, if they intersect at any point, they will intersect in the line y=x. So you can just let f(x)=x and solve or you could even let f^-1(x)=x and then solve.
thank you very much

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