Thread: One to one functions

Hello all

I'm learning one to one functions in class now and i had a few questions that i'm a bit lost in =/

I have a problem in the book that says to use the Inverse Function property to show that f and g are inverses of each other.


The first question is

f(x) = x - 6, g(x) = x + 6

Well I did two different ways other than using the Inverse Function property

First I picked a random x value for f using 2. So f(2) = x - 6 which is -4.

Next I plugged in -4 to g(x) to get -4 + 6 which is 2. So this shows they are inverses.

The second method I used was, i just found the inverse function of f(x) = x - 6

y = x - 6

y + 6 = x

x + 6 = y which shows it is also inverse. My question is how do i use the Inverse Function property to check? Thanks

Originally Posted by JonathanEyoon

Hello all

I'm learning one to one functions in class now and i had a few questions that i'm a bit lost in =/

I have a problem in the book that says

Assume f is a one to one function

If f(2) = 7, find f^-1(7)

f^-1(7) means what should x be so that f(x) = 7. In this case it is x=2. Because f(2)=7 like the problem says.

If f(x) = 5 - 2x, find F^-1(3)

Do the same thing here. What does x be so that f(x)=3. Meaning 5-2x=3.

Originally Posted by ThePerfectHacker

f^-1(7) means what should x be so that f(x) = 7. In this case it is x=2. Because f(2)=7 like the problem says.


Do the same thing here. What does x be so that f(x)=3. Meaning 5-2x=3.

I managed to figure those out. It was a lot easier than it looked hehe. I appreciate the help!! Think you could help me with my new question? I edited my original post.