Question

help medal

Answer 1

*getting a sore neck* lol

OK, F(x) = 3x + 6

We've done other problems like this, so what's the first step? Put the question in y=f(x) notation, e.g.

y = 3x + 6

Answer 2

move the x and y

Answer 3

Now, an inverse swaps the domain and range of a function. So this is where NORMALLY we would change the x to a y and the y to an x.

However, as we've talked about before, your teacher seems to want you to give the inverse as a function of y (not standard... you might ask about that???) so you should really just SOLVE FOR x.

Answer 4

remember last time you help well i got all of them wrongg -_-

Answer 5

Well, if you mean switch the x to y and the y to x, that's hard to answer here because of your teacher's unusual notation.

Normally the inverse of the function F(x) is given by \(F^{-1}(x)\), not as \(F^{-1}(y)\). But since your teacher used the notation \(F^{-1}(y)\), I'm assuming that (s)he wants it to be a function of y.

Answer 6

OK, 2 questions:
1. how did you do it last time? did you give your answer as a function of y, or of x?
2. Did you ask the teacher why they were all wrong? Did you get any feedback?

Because that goofy notation is really throwing me. I can explain it either way, but I'm not sure what your teacher wants.

Answer 7

did u see the pic what it telln me to solve for

Answer 8

Yes, I saw the picture. The picture says to find "the inverse of F(x)"... that's cool, I know how to do that. But that is called \(F^{-1}(x)\), NOT \(F^{-1}(y)\) as your teacher's notation says.

\(F^{-1}(x)\) is a function of x, and that is how the inverse of a function of x is normally given.

\(F^{-1}(y)\) would be a function of y.

Answer 9

ok im lost

Answer 10

ACTUALLY, \(F^{-1}(y)\) SHOULD be the function I get, if I take an inverse of a function of y.

E.g., if I have a function \(F(y)=3y-7\) and I take it's inverse, THEN I should get a function that I would call \(F^{-1}(y)\). The inverse of a function of x should be a function of x; the inverse of a function of y should be a function of y.

The inverse of a function of x should not be a function of y.

Answer 11

*sigh* I know you are, and I'm sorry. Finding the inverse of this function is NOT hard. It's just the notation being used by your teacher that is making it complicated. So let me ask again:

OK, 2 questions:
1. how did you do it last time? did you give your answer as a function of y, or of x?
2. Did you ask the teacher why they were all wrong? Did you get any feedback?

Because that goofy notation is really throwing me. I can explain it either way, but I'm not sure what your teacher wants.

Answer 12

@amistre64 @AkashdeepDeb have either of you seen this weird kind of notation for the inverse before? Any thoughts??

Answer 13

yes, there is still debate about it :)

Answer 14

the inverse of f(x) is such that the values that relate to x are a function composed of y values

Answer 15

LOL so do you think he should just solve the equation as-is for x, and let that be the inverse, x as a function of y?

Answer 16

How much is? F^-1(x) guys?

Answer 17

f(x) = 3x+6

f(x) is some curve in the xy plane such that for any given value of x gives us a value such that y = f(x)

y = 3x+6 , the inverse of this setup is such that: (y-6)/3 produces the values of x that relate to inputs of y

Answer 18

i believe that he should simply solve for the inverse and keep it as a function of y ...

Answer 19

Can you please tell me the value of
F^-1(x) ?

Answer 20

can someone teach me how to solve please

Answer 21

Thanks for the input. @AkashdeepDeb I didn't understand your question... lol.

I'll have to read up on this, as I've always taught it with switch and solve.

Answer 22

spose \(f:X\to Y\) and \(g:Y\to X\) such that \(f\) and \(g\) have an inverse relationship to each other .... etc

Answer 23

http://www.mathsisfun.com/sets/function-inverse.html

Answer 24

@AkashdeepDeb \(f^{-1}(x)\) maps the element x in the range of F back to x in the domain of F....?? I'm not sure what you're looking for. Maybe we should take this to another post so as not to give @romanortiz65 nightmares, lol.

Answer 25

yup xD im totaly losttt

Answer 26

@romanortiz65 here is what you need to know:

You have y = 3x+6

Solve it for x, so you will have x={some stuff that involves y}

Then that is your \(f^{-1}(y)\), eg,

\(f^{-1}(y)=\text{{some stuff that involves y}}\)