Given f(x) = (3x-1)/2 Solve for f^1 (4)

Question

Given f(x) = (3x-1)/2  Solve for f^1 (4)

anonymous · Answer

@jim_thompson5910 @Hero @phi @zepdrix @.Sam. @timo86m @jdoe0001

zepdrix · Answer

$$\Large f(x)=\frac{3x-1}{2}$$

Solve for `f^1(4)`

Did you mean to write $\Large f^{-1}(4)$ ?

anonymous · Answer

No, its: $$f ^{1} (4)$$

zepdrix · Answer

What is the 1 suppose to signify? Is that a first derivative? :o

anonymous · Answer

I have no idea, that was the question I was given.

zepdrix · Answer

Hmm, weird. :(

anonymous · Answer

The answer choices are:

a. 1
b. 3
c. 5
d. 7

ness9630 · Answer

What class are you in?

anonymous · Answer

Algebra 2

ness9630 · Answer

Well it can't mean derivative, that's for sure.

anonymous · Answer

So how do I solve this then?

ness9630 · Answer

@zepdrix I know you're smart.. any ideas?

zepdrix · Answer

I think it was a typo, I think it was supposed to be f^-1(-4).
Was this from a book, or like something your teacher assigned? :o

Have you learned about finding inverses yet troy?

ness9630 · Answer

Wait.. hold on! I think it was suppose to be f^-1 like zep says.. it gets you one of the answer choices you listed.

Watch, try it:
$$f(x)=\frac{3x-1}{2}$$
$$x=\frac{3y-1}{2}$$
Solve for y and you get this:
$$2x=3y-1$$
$$2x+1=3y$$
Divide:
$$\frac{2x+1}{3}=f^{-1}(4)$$
Can you finish it?

anonymous · Answer

I like just started this course, I haven't really learned much yet.  It's mostly just review of Algebra 1 from a couple years ago, which I can't remember anyway.

ness9630 · Answer

Do you understand what I just did though?

anonymous · Answer

No.. not really.

ness9630 · Answer

What I did first was switch y and x around, since that's what solving for an inverse is. Then I just solved for y again.

anonymous · Answer

Ok, so how would I get to the answer?

ness9630 · Answer

You see that very last equation? f^-1(4)
Just plug in 4 for x and you will get it.

anonymous · Answer

So, 3?

ness9630 · Answer

Yup!

anonymous · Answer

Thanks!  I've got another for you, if you don't mind.  

On the graph of the equation 4x + 5y = 2, what is the value of the y-intercept?

ness9630 · Answer

The y-intercept is just when x=0

anonymous · Answer

The choices are:

a. -5
b. -4
c. 4
d. 5

ness9630 · Answer

That's strange.. it's not one of the choices

anonymous · Answer

The answer is 4, you have to graph the equation and tell what number is on the y-intercept.

anonymous · Answer

The next question is: 
Graph: tinyurl.com/mrr8dcb
Find the average rate of change for the given function from x=1 to x=2.

ness9630 · Answer

I have no access to connexus

anonymous · Answer

Sorry, one second

anonymous · Answer

here:

ness9630 · Answer

Just find the slope:
(1, 3) (2, 6)

anonymous · Answer

4 isn't and option.

anonymous · Answer

a. -2
b. -1/2
c. 1/2
d. 2

ness9630 · Answer

Whoops, it's suppose to be (1, 3)(2, 5)

anonymous · Answer

Oh, ok

anonymous · Answer

So it's 2?

ness9630 · Answer

Yup!
Unless I'm losing my skills

anonymous · Answer

haha hopefully not!  Ok, I got another one.
(Use the table below to answer the question)
Find the average rate of change for the given function from x=1 to x=3

ness9630 · Answer

I think for that one you would find the slopes for each, then add and divide the slopes

anonymous · Answer

Ok.  Thanks for all your help!

ness9630 · Answer

Anytime!