[MOVED] Inverses of linear function: f(x) = (9/5)x + 32

T

tek

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To determine the temperature on the Fahrenheit scale if you know the Celsuis scale, you can use the function f(x) = (9/5)x + 32. Determine the inverse of the function and explain what it represents.

How would I plug in the function they give to get the inverse of the function?
 
I don't know what you mean by "plugging in" the given function. What would you plug, and into what would you plug it...?

Instead, try using the inversion technique they showed you in class and in your textbook. It almost certainly ran something like this:

. . . . .i) Rename "f(x)" as "y".

. . . . .ii) Solve for "x=".

. . . . .iii) Switch "x" and "y", so you have "y=".

. . . . .iv) Rename the new "y" as "f<sup>-1</sup>(x)".

If you have trouble with this procedure, please reply showing how far you have gotten. Thank you.

Eliz.
 
is this right how i am doing it

f(x)=9/5x+32

x=9/5x+32

x-9/5

9/5-9/5

x-9/5 y=x-9/5
------- --------
32 32
 
Why did you rename "f(x)" as "x"? This reduced you from a two-variable function to a one-variable equation. Where did "y" come from, at the very end?

I don't know what method you're using...? Please either provide that method (typing out all of the steps in the instructions, so we can see what you're trying to do), or else try following the steps provided earlier.

Thank you.

Eliz.
 
ok is this right so far

f(x)=9/5x-32

1.y=9/5x-32

2.x=9/5y-32

2.x-9/5

2. 9/5-9/5
 
Okay, you've now done the first step correctly: you've renamed "f(x)" as "y". Now you need to try to do the second step: Solve "y = (9/5)x - 32" for "x=".

Eliz.
 
for the second step would u subtract 9/5 from y or would it subtract form 32.

this part is getting me confused . i'm sorry i just not very good at this.
 
Since the 9/5 is not added to the x, no, you would not subtract it from anything. I'm not sure what you mean by "would it (what?) subtract form ("from"?) 32"...?

Have you studied solving linear equations at all...? If not, we need to get you caught up on that topic, first, before you can start solving literal equations.

Thank you.

Eliz.
 
i think your way is right but our teacher has us subtract the the number from the x like i did before. he always makes the answer x-number
----------
number
we just got into this.


can u explain how do the second step like give me an example for i know how to do the second step for my problem.
 
tek said:
our teacher has us subtract the the number from the x...
Click to expand...
If your instructor is telling you to get rid of factors by subtracting, then it's no wonder you're confused, because that would never work.

To learn how to find inverse functions, try reading this.

Eliz.
 
f(x)=9/5x-32

1.y=9/5x-32

2.y - 9/5
--------- =x
-32

y=x - 9/5
---------
-32
 
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