The Round Trip Theroem basically says that if a one-to-one function [f(x)] has an inverse function [g(x)], then two things should be true. One: f(g(x))=x, for every x in g's domain. Two: g(f(x))=x for every x in f's domain.
So for Number 25, you have to show that g is the inverse of f by proving the f(g(x))=x and g(f(x))=x. Since f(x)=1/(x+1) and g(x)=(1-x)/x, g(f(x))= (1-(1/(x+1)))/(1/(x+1)). (I know that's a lot of parentheses, by if you simplify by hand or by using your calculator, it should equal x!)
Do the same thing to simplify f(g(x)) and you've used the Round Trip Theorem to prove that g is the inverse of f!
3 Comments:
The Round Trip Theroem basically says that if a one-to-one function [f(x)] has an inverse function [g(x)], then two things should be true. One: f(g(x))=x, for every x in g's domain. Two: g(f(x))=x for every x in f's domain.
So for Number 25, you have to show that g is the inverse of f by proving the f(g(x))=x and g(f(x))=x. Since f(x)=1/(x+1) and g(x)=(1-x)/x, g(f(x))= (1-(1/(x+1)))/(1/(x+1)). (I know that's a lot of parentheses, by if you simplify by hand or by using your calculator, it should equal x!)
Do the same thing to simplify f(g(x)) and you've used the Round Trip Theorem to prove that g is the inverse of f!
thanks
Right on, Casey Blue!
Post a Comment
<< Home