Step-by-step explanation:
Given two one-to-one functions f(x)f(x) and g(x)g(x) if
(f∘g)(x)=xAND(g∘f)(x)=x(f∘g)(x)=xAND(g∘f)(x)=x
then we say that f(x)f(x) and g(x)g(x) are inverses of each other. More specifically we will say that g(x)g(x) is the inverse of f(x)f(x) and
denote it by
g(x)=f−1(x)g(x)=f−1(x)
Likewise, we could also say that f(x)f(x) is the inverse of g(x)g(x) and denote it by
f(x)=g−1(x)
Given the function f(x)f(x) we want to find the inverse function, f−1(x)f−1(x).
First, replace f(x)f(x) with yy. This is done to make the rest of the process easier.
Replace every xx with a yy and replace every yy with an xx.
Solve the equation from Step 2 for yy. This is the step where mistakes are most often made so be careful with this step.
Replace yy with f−1(x)f−1(x). In other words, we’ve managed to find the inverse at this point!
Verify your work by checking that (f∘f−1)(x)=x(f∘f−1)(x)=x and (f−1∘f)(x)=x(f−1∘f)(x)=x are both true. This work can sometimes be messy making it easy to make mistakes so again be careful.
Step-by-step explanation:
Setting y=f(x)
y=xx−2
this may be rearranged (intermediate steps shown) as follows
y(x−2)=x
x⋅y−2y=x
x⋅y−x=2y
x(y−1)=2y
x=2yy−1
This expression shows x in terms of y.
That is,
f−1(x)=2xx−1
Setting y=f(x)
y=xx−2
this may be rearranged (intermediate steps shown) as follows
y(x−2)=x
x⋅y−2y=x
x⋅y−x=2y
x(y−1)=2y
x=2yy−1
This expression shows x in terms of y.
That is, it is the inverse of function f(x).
That is,
f−1(x)=2xx−1
as required.